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01 May 2019

43. seen and not heard

Im wunderschönen Monat Mai,
Als alle Knospen sprangen,
Da ist in meinem Herzen
Die Liebe aufgegangen....

[In the wondrously beautiful month of May
as all of the buds were bursting,
then in my heart
love unfolded.]

The opening quatrain of Heinrich Heines Lyrisches Intermezzo (1823) is stirring enough, but it is almost a cliché to point to the beginning of Robert Schumanns song cycle Dichterliebe (1840) as reaching heights (and depths) that Heines words cannot.  The unutterable longing expressed somehow in the initial piano figure, wavering back and forth in a repeated (it seems) Phrygian half-cadence, D – C-sharp – D – C-sharp in the bass, until it suddenly resolves not into F-sharp minor (to which our ear may be leading us) but with disarming ease into A major.  (A recording is available from the IMSLP here.)

SOURCE: cropped scan of first edition of Dichterliebe (Leipzig:  Peters, c. 1844), p. 3, from IMSLP #25011.
Schumann pointedly leaves this figure unresolved when it returns at the end of the song, the ambiguity persisting several seconds into the next song (again resolving in A major).  It is a great momenthauntingly beautiful, as I suppose it is intended to be.  And, because of such inspiration, Schumanns place among the canon is secure.  Or is it?  After all, the canon is really just whoever we say it is.

I moved to Virginia in July 2017, and a few weeks after I arrived white supremacists gathered in Charlottesville, about 60 miles away, for a demonstration that turned deadly and seized headlines all over the world.  Appalled and repulsed, I watched white menpeople who look like meproclaiming their entitlement, endeavoring to reclaim privilege they regarded as their birthright.  Even as they chanted their vile slogans, I was working on my syllabus for the second part of a two-semester music history survey for music majors I would start teaching later that month.  As I struggled to pack far too much essential content into a semester, I wistfully thought of all the things I wouldnt have time to talk aboutthings that revealed that the claim of entitlement on rampant display a short drive away was really a recurring story in music history.  (Jews will not replace us! is the essence of Richard Wagners notorious 1850 essay Das Judenthum in der Musik.)  Us versus them is, indeed, the story of so much history that its continuing manifestations in the headlines now seem more akin to DOG BITES MAN” than to MAN BITES DOG.”  But when, as is the rule rather than exception in history, the violence is perpetrated by those in power against those excluded from it, the news must always be shouted from the rooftops.

And so in my first year teaching in Virginia I introduced an overhaul to the music history sequence, jettisoning the soup-to-nuts survey from plainchant to the present (an approach which gives students a false sense of comprehensiveness).  Instead I used the allotment of two semesters for a different approach:
  1. For Music History I:  genres and forms, I concentrated on only two genres, a mini-survey that allowed us to trace genre-specific traits and innovations over a shorter time period.  I selected concertos and song cycles as our twin foci.  Those were not easy choices, but they allowed me to focus on contrasts between domestic and public music-making, to consider text-setting as well as non-texted music, to have the students learn to navigate orchestral scores as well as (sometimes equally bewildering) keyboard writing.  Although the chronology of the song-cycle is particularly restrictedbasically starting in the early nineteenth centuryI reached back to solo cantatas and other works that could be seen as antecedent (though not really ancestors) of the genrejust as I brought in concept albums as a continuation of the tradition.  Even with only two genres, I found that I had the same impossibility of fitting everything I wanted to discuss into a single semester.
  2. For Music History II:  narratives and ideologies, I wanted a course that was basically What lessons can we learn from music history?  Two of the questions considered in that course were pulled directly out of my reactions to the white nationalist rally:  How does a composer become a privileged voice, and who gets suppressed in the process?  and If we view music history not in terms of composers or even of performers but rather of patrons, what does the landscape look like?  Inextricably part of both of these is gender, and there were plenty of good reading assignments to provoke them to think about the propped-up nature of the canon of Great Composers which we had all inherited.
As will be clear from this blog, Great Composers is (sic) very much my bread and butter.  Even in my first post I tried to be candid that dead white males would inevitably dominate my posts, if for no more nefarious reason than their music generally has a longer paper-trail.  That said, I have been keenly and uncomfortably aware that I have yet to post about the music of a female composer (even though a number of female editors have come up).  As we begin Heinewondrously beautiful month of May, however, I make this humble effort to emend my ways.

Does this sound familiar?  (Listen to it here.)
SOURCE:  cropped scan of p. 41, II/3136 (Breitkopf, 1990).
This is from the slow movement of the Piano Concerto in A minor, op. 7,  by Clara Wieck (later Clara Schumann).  She wrote this in about 1835, and it is a striking anticipation of Robertwunderschönen Monat Mai figurethe same two harmonies wavering back and forth, even expressed in the same key.  Is it too much to say Robert stole it from her?  He clearly knew the piece well.  An inside joke?  An unintentional derivation?  Common property of husband and wife?  Admittedly Wieck doesnt use this gesture to slip into A major, as Robert was to do.  More remarkably, this is part of a transition to A-flat majorvery far removed from her home tonic.  Indeed, Claudia Macdonald quotes an early reviewer who attempts a chauvinist joke about this:
Women are moody.... [I]f in their cherished domestic and matrimonial circumstance the daughters of Eve would make no other, larger leaps, deviations or evasions than such a teensy half step, then everything would be just fine.
[Allgemeiner musikalische Anzeiger 
in 1838; trans. Macdonald, p. 31]
Did Robert face this sort of nonsense when, in his piano Phantasie for piano and orchestra (also in A minor, and later revised as the first movement of his own concerto in that key) he also modulated to A-flat major?  Or was that just genius?  Granted, Roberts choice of A-flat may be dictated by a strategy to emphasize melodic unity:  he preserves C-natural as the third scale degree, on which he begins his motive whether in its home minor key orwith the tonic lowered by a half-stepin major:
SOURCE:  composite from Robert Schumanns Werke, Ser. III (Breitkopf & Härtel, 1883--from IMSLP #291223), pp. 147 and 159, with my own indications of the opening of the Ur-melody in each key.
Still, there is something about the same tonal maneuver (A minor to A-flat major and back) in both works that to me has a sense of anything you can do, I can do better about it.

SOURCE:  Clara Wieck, aged 16, with the finale
of her concerto on the music desk before her;
lithograph by J. Giere, scan from
Europeana Collections
Much as I love and admire the work, I did not include Roberts piano concerto in my music history class; I featured him instead in the song-cycle part of the course.  I did, however, use Wiecks concertoa work hitherto completely unknown to me.  Her anticipation of the wunderschönen figure arrested my attention, but I was equally struck by very many blog-worthy textual details.

The source situation is pitiful:  no autograph from Wieck survives; the only manuscript that survives is Roberts and is fragmentary, as it seems he orchestrated her finale.  (Like his own concerto later, Wiecks work started as a one-movement Concertsatz, though in her case it was what would later be the finale.)  There is no extant manuscript of any sort for the first or second movement, and until 1990 the only edition of the work was its first one, published by Hoffmeister in about 1836, and handily available on the IMSLP (#566786).  (A 1987 edition reproduced a manuscript full score apparently derived from the Hoffmeister parts.)   Ill come back to the original edition below.

More than anything else, I have been intrigued and fascinated by rhythmic details of Wiecks score.  Note, for example the stunning variety of rhythms in the piano sprays tossed off hereat a tempo that make these differences barely perceptible to the audience:
SOURCE:  highlighted cropped scan of p. 58, III/7379 (Breitkopf, 1990).
(I also like the way the bassoon accumulates longer and longer statements, starting from just the initial motive of the main theme.)

I also noted places in which the solo part has very slightly different rhythms from other instruments doubling the same idea.  In this example, I think she has accommodated the large left-hand jump made across the bar-line:
 SOURCE:  highlighted cropped scan of p. 52, III/4144 (Breitkopf, 1990).

A similar motivation seems to be behind these alterations:
SOURCE:  my composite from details of pp. 2324, I/9497(Breitkopf, 1990).

But I confess that I am flummoxed about what to make of this rhythmic notation [though see ADDENDUM]:
SOURCE:  highlighted detail of p. 41, II/3739 (Breitkopf, 1990).
The illustrations above come from the new edition issued by Breitkopf & Härtel in 1990, edited by Janina Klassen.  As I compare the cover pages of the original Hoffmeister and the new edition [below], I wonder if Breitkopfs decision to refer to her only by her married name isnt just a marketing ploy, linking her music to the canonic name of her famous husband.  She was not yet married when it was first published, and her name was much more widely known than Roberts was at the time.  She was a pianist of international renown already at a young age.  Indeed, she was just sixteen when she premiered the complete work on 9 November 1835 with Felix Mendelssohn conducting at the Leipzig Gewandhaus.

Despite the many virtues of the new edition, the Hoffmeister original is particularly useful in the classroom, as it exemplifies the practical publication of this sort of work in the nineteenth century.  In place of a full score, the piano part includes orchestral cues throughout (and, as the title page indicates, could serve for rendition of the work by piano alone); the first violin part is similarly cued to facilitate directing a performance; all the string parts have small-note alternate lines to enable the piece to be performed with only a string quintet accompaniment.  Here, for example, is the bottom of the first page of the violin part, bearing the instruction that notes marked avec Quintuor (as on the second staff) are for this chamber version, while the other instrumental cues are only there to assist a violinist/conductor:
SOURCE:  C. Wieck op. 7, detail of Vln. I p. 1 (Leipzig, Hoffmeister, c. 1836) from IMSLP #566786 [p. 29]
In the absence of any other sources, it is impossible to know whether the quintet adaptation is Wiecks or Roberts, or maybe even an in-house job by the Hoffmeister firm.  Indeed, in the absence of any other orchestral works by Wieck, we cannot even make a guess about whether the orchestration in the first movement is her own.  I have been puzzled by remarks such as Whether [Robert] Schumann orchestrated the other movements is not known:  except for a solo cello, the orchestra is entirely silent in the second movement.  Sometimes I suspect that we musicologists get so caught up in the commentary that we fail to perceive at the very music we study.

This is only one aspect of a problem musical women (whether composers, performers, or patrons) have faced for a very long time:  seen and not heard, recognized but not valued, subject always to the male gaze but essentially invisible.  (For a recent ripped-from-the-headlines example of an analogous situation, see Imani Mosley's perceptive reflection on the erasure of Peter Pears from the public face of the Benjamin Britten legacy.)  I am grateful for initiatives that facilitate addressing this issuefor example the Institute for Composer Diversity and the database Music Theory Examples by Women—and for writings by Cyrilla Barr, Ralph Locke, and Marian Wilson Kimber (among many others) that I now view as required reading for my students.  Systemic prejudice against women composers; exclusion from educational, performance, and career opportunities; dismissal of womens musical activism as mere volunteerism; and critical approaches that cite women merely as also-rans are just some of the factors that have unfairly shaped the music historical narratives.  That is a much more important thing for my students to learn than any particular masterwork of the repertory.

ADDENDUM  2 May 2019

Regarding the impossible rhythmic notation I note above, I thank William van Geest for directing my attention to this 2011 article by Julian Hook, in which the Wieck seems to be the earliest example among many similar examples from within the larger Schumann circle: 

01 April 2019

42. yet there’s method in’t

I toyed with a spoof post for April Fools Day; I even considered altering the nameplate to read Suppurating Sores, but ultimately thought better of it.  You can thank me later.

Im just back from the annual conference of the Society for Textual Scholarship, which this year was hosted collaboratively by NYU and The New School.  It was my first time attending this conference and I intend to return.  I knew that this time if I wasnt giving a paper, I would be just standing along the wall during the breaks, drinking coffee and eating bagels.  So I went back to Bach’s so-called “passaggio chorales,” about which I have already posted on the blog.  This time, though, I looked more at the earliest sourcesall manuscript copiesrather than the nineteenth- and twentieth-century editions (the focus of my earlier post).  My conference proposal was to link some textual issues in these manuscript copies with theories that have emerged around the so-called bad quartos of the Shakespeare plays:
  • reported texts—pirated memorial reconstructions by an actor or some other party; 
  • deliberate abridgments to shorten the drama (or calculated to require a smaller cast);
  • versions derived either from the author’s “foul papers” or subsequent revisions; 
  • socialized theatrical texts versus idealized literary ones;
  • “performing the play into shape”; 
  • texts flawed in the printing shop; or
  • some combination of any of the above
(The line I quote in this post’s title isn’t in the first quarto of Hamlet.  In that source Corambus (the character in later sources known as Polonius) remarks merely Very shrewd answers.”  A lot of Hamlets best-known lines arent in Q1, so it is naturally suspected to be bad,” as it doesnt present what we would like Shakespeare to have written.)

Although the textual situations of Shakespeare and Bach are very different in many respects, I posited that the scholarly theories developed around the one may yet shed some insight on the textual situation of the other; or at least I hoped that my abstract submission might intrigue the program committee enough to get me a spotand it did.  It was a stimulating meeting, with ideas and findings from presentations that will be re-echoed here in the months and years to come.  Somewhat pressed for time for this post in the middle of the academic term, I will extract just one curiosity from my own presentation.

The passaggio chorale represents a style of hymn-accompanying in which the organist played short interludes between sung phrases of the hymn.  These interludes need not necessarily be showy—still less very longbut they would somehow need to negotiate a path to the next sung note.  Georg Friedrich Kauffman’s Harmonische Seelenlust (published serially in Leipzig 1733-1740) includes 63 passaggio settings, along with more figural chorale settings.  Here is an example, Kauffmann’s passaggio setting of “Gelobet seist du, Jesu Christ.”
SOURCE:  Kauffmann, Harmonische Seelenlust (Leipzig, 1733ff.), detail of p. 31; scan from Bach-Digital.
That this setting was intended for accompanying singing is strongly suggested by the “turn-around” interlude after the double bar, which leads back to the first note of the chorale (indicated by a custos at the end of the staff, as is the return of the first bass note).  None of the extant settings attributed to Bach have that “turn-around,” and it is not absolutely clear that they even are intended for congregational singing, but they do manifestly allude to the same tradition in which Kauffmann was working.

Note that Kauffmann’s settings were published in a figured-bass format.  Bach’s six extant settings are transmitted in figured bass only in one source, a copy by Johann Tobias Krebs preserved in an album in the Berlin Staatsbibliothek, P 802.  The traditional view has been that Krebs was preserving an incomplete or draft version, while the fully-realized texts preserved by others represent Bach’s finished version.  Part of my argument at the conference—and I am not the first to make it—was that it ain't necessarily so.  Assuming that there even was a lost Bach autograph behind these pieces, there is simply no reason to suppose that it was anything more than the figured-bass lead sheet Krebs gives, rather like Kauffmann’s published settings.

Be that as it may, I was pleased when two other tidbits of my research converged to demonstrate that the contemporaneous uses of the Bach settings played fast and loose with the notion of these pieces as autonomous works.  A curious source that has often been discussed before is the third fascicle of P 274, a c. 1724 copy by Johann Peter Kellner of a Bach Prelude and Fugue (BWV 531, although somewhat abbreviated), after which Kellner copied just portions of two of the passaggio chorales.  Below, I have highlighted in yellow the double bars that indicate the end of BWV 531/ii.  The red markings that follow it link up the copied fragments from BWV 722 (Bach’s “Gelobet seist du”) with the BG edition of the same; the sections marked in blue are taken from BWV 732 (Lobt Gott, ihr Christen allzugleich).  As I say, these fragments have long been known, as has a third-party copy which transmits the text of Kellner’s copy remarkably faithfully—fragments and all.
SOURCE:  (left) BG Vol. XL, p. 62, from scan IMSLP #549819; (right) p. “25” of P274 fasc. 3, from Bach-Digital.
The text Kellner deemed worth preserving here was apparently not the chorale harmonization but just the sorts of figures that Bach used for the interruptions (mainly scales and arpeggios).  The one bit of  harmonization from BWV 722 which is preserved is unusually ornate, with a melodic motive appearing in the bass-line as well as within the harmony; Kellner must have liked that idea.  He probably could have played an approximate version of BWV 722 from just his notated fragments—supplying the bulk of the chorale melody and harmonization himself; but the two interludes from BWV 732 following it hardly give enough substance to recreate that setting.  No, a “memorial reconstruction” of anything like the original seems not to have been his goal.  What was it then?

Among the more recent work on the Shakespeare quartos has been a reconsideration of the interaction between literary and oral tradition, and the consequences such would have on the text performed—or at least in the text as printed.  Such ideas are not new to musicologists:  in the 1970s Leo Treitler and others were applying the “formulaic composition” theories of Albert Lord and Milman Parry to plainchant transmission.  If, however, we recognize the passaggio chorale genre as essentially formulaic—each phrase of the harmonized chorale interrupted by elaborate flourishes—then it is not hard to see how such flourishes might become “licks” that could be used to construct new settings (not necessarily notated, but readily performed).  Kellner was preserving the bits he wanted to use.

There is actually more documentary evidence for this mix-and-match approach.  The volume now known as P802 is the work of three different hands:  Johann Tobias Krebs; his son Johann Ludwig Krebs; and Johann Gottfried Walther.  These are Weimar sources (although J. L. Krebs followed JSB to Leipzig to study under him there).  P802 is a thick album:  368 pages containing at least 85 chorale settings, with a range of composers including Pachelbel, Buxtehude, Böhm, Bruhns, Weckmann—the usual suspects for North German organ music c. 1700—plus the newer figures Bach, Kauffmann, and the copyists themselves.  Scattered among all of these pieces are two unattributed passaggio settings, and it is perhaps their anonymity that has left them more-or-less unstudied over the years.  Penned in the hand of Krebs the elder, the second uses the same figured-bass notation that he used for BWV 722, but the first one does not even include a bass-line.   (That said, it may not be accurate to describe it is as incomplete, as one could easily improvise a harmony from what is given—that is, the harmonization is left completely to the player.)  Significant here, however, is that every one of the interludes is taken from one or other of the four Bach passaggio chorales transmitted by Krebs.
SOURCE: scans of P802 from Bach-Digital, marked-up to identify Bach quotations; (top) “Herr, wie du willst, so schicks mit mir (p. 230); (bottom) Jesu, der du meine Seele (p. 253)
That there is a similarity between some of these interludes and Bach’s has been noted already by Schulenberg (in Bach Perspectives 1) and Zehnder (in Bach-Jahrbuch 2013), but I can’t find anyone noting that indeed all of these interludes are ripped from Bach’s settings, some only very slightly adapted to fit the new harmony.

Compared with Shakespeare—for whom basically no autograph material survives—the Bach textual situation is pretty good.  Surviving sources include quite a few autographs, a few original prints, and loads of material copied by people (like Krebs) closely connected to the composer.  But in the absence of an autograph—as in the case of the passaggio chorales—we are forced back to the question Shakespeare scholars have been confronting for centuries:  “What did X write?  And what sorts of clues can the surviving sources give us to answer that question?”  As with Shakespeare, in the case of these Bach pieces—if indeed they are by Bach—we have a fundamental break in the transmission at the very top of the stemma:  no autograph.  (Saying this presumes, of course, that there was an autograph manuscript at all.  In the case of the passaggio chorales, however, there need not have been:  what if we are not talking about texts of a work, but rather records of a practice?  A question to return to in another post….)

The abbreviated texts transmitted by Krebs ultimately take us back to eighteenth-century practice, whether or not it is what Bach wrote.  Thus, I echo Steven Urkowitz on the bad quartos:
[W]e all would learn more about Shakespeare’s plays if we look at the actual raw material, the variant quarto and Folio versions.  Even if … corrupt alternatives [were] introduced by pirates or players, at least those pirates or players stood through repeated performances of Elizabethan plays in Elizabethan playhouses. (p. 204)
Mutatis mutandis, Krebs was there; Kauffmann deemed the abbreviated format adequate for his own publications; and we don’t even know that the fuller version is Bach’s and not actually by Walther or some Herr X.  Krebs gives us merely a starting point, but it seems likely to take us closer to Bach’s own practice—to the extant anyone is seeking it—than the standard text of so many critical editions.  Rather like Shakespeare’s situation,  perhaps we need to keep in mind that (borrowing from the words of Graham Holderness and Bryan Loughrey) “the earliest versions of [Bach’s] works existed in plural and contested forms.”

01 March 2019

41. audacity

I recently came across Richard Egarrs recordings of the Handel organ concertospieces I have known for decades, but that I learned first from the recordings of E. Power Biggs (with Adrian Boult) and Simon Preston (with Trevor Pinnock).  Much as I respect and enjoy Biggs and Preston, the Egarr recordings have a impetuous audacity that strives to emulate the (basically unwritten) example of the composer.

To take only the most striking example, at the end of the second movement of Op. 7 no. 4, where Handels instruction reads merely Organo ad libitum, Egarr uses that rarest of intervals, the doubly-augmented unison/octave, to effect the modulation from D to F major, for his interpolated slow improvisation.
SOURCE:  my transcription of this moment (the transition from Track 15 to 16) on disc I of Egarrs recordings of Handel's Op. 7 (and more) with the Academy of Ancient Music; Harmonia Mundi HMU 807447.48 (2009).  The recording is streamed on Spotify here.
I spell it thus (D-sharp against D-flat) because that is how these notes are functioning:  chromatic side-steps up from D to E and down from D to C.  The resulting passing dissonance should not be spelled as a diminished third (which would indicate converging rather than expanding motion); a major second would be meaningless.  Audacious is the only word.  The interval is not part of Handels musical style, but it has the (I think) appropriate consequence of directing the spotlight onto the soloist.  What will he do next?

Handel himself seems to have relished the spotlight:  he used his organ concertos mainly in performances of his oratorios, where during the breaks between sections he could have all the attention to himself.  But he wasnt above stealing the show from his highly-paid vocal soloists.  His first London opera, Rinaldo (1711) includes a remarkable moment at the end of Act II when Handel apparently wanted to divert the attention at least temporarily from the stage to the pit.  His autograph of the aria Vo far guerra has disappeared, but the early copies indicate that in the opening ritornello there was to be an extended extempore passage for harpsichord (Cembalo), for the composer himself to display his gifts:
SOURCE:  Opening of Vo far guerra (Rinaldo, Act II) in a copyist’s manuscript held by the British Library (f. 91r of R.M. 19.d.5); scanned from Graham Pont, “Handel versus Domenico Scarlatti:  music of an historic encounter” in Göttiger Händel-Beiträge IV (1991), p. 234.
Susan McClary famously characterized the texture of the first movement of Bachs fifth Brandenburg concerto as one in which the harpsichord, which first serves as continuo support then begins to compete with the other soloists for attention, and finally overthrows the other forces in a kind of hijacking of the piece [p. 28].  How much more audacious was it for Handel to upstage the singer of an aria, left lingering on stage while the composer showed off?  The aria includes collaborative passages in which the soloist and the harpsichord run in parallel as a sort of duet, and where Signora Pilotti (for whom this aria was written) holds a note for several bars while a harpsichord obbligato is conspicuously busy underneath, but there is another totally free sectionleft to the discretion of the soloistin the closing ritornello, while again the singer is left at loose ends on stage.  Moreover, as it is a da capo aria, all this happens twice (with, presumably, different extemporizations). 

We do not know what Handel played in these ad libitum episodes, but I expect they could not have been lasted very long, as otherwise there would surely be some press comment.  The Spectator famously lampooned the first production of Rinaldo, but no mention is made of excessive keyboard virtuosity in those reviews.  Perhaps later in the run the solos became more extended and showy; certainly theres no reason to assume that he always played the same thing.

When Chrysander published Rinaldo in the old complete works (HG vol. 58 in 1874), he had the portions of the autograph preserved in the Royal Music Library, and copies like that above, and so his edition has the same Cembalo instruction with no indication of what to play.  After doing a little more legwork and tracking down more sources, he published Rinaldo again (HG vol. 58 [bis] in 1894), including both the 1711 and 1731 versions.  Vo far guerra was cut from the 1731 version, but for the 1711 version this time Chrysander added an appendix with a complete realization of the harpsichord solo:
SOURCE:  detail of revised edition of HG vol. 58 (1894), p. 117; from IMSLP #18974
If we look up the aria in the new HHA volume presenting the 1711 version of Rinaldo, an almost identical realization is given not in an appendix but in the main textwithout even a footnote to indicate that its source is not easily authenticated.  One has to look elsewhere in these scholarly editions to find that the Harpsichord piece performd by Mr Hendel comes from a keyboard arrangement, Songs in the Opera of Rinaldo; this was originally published by John Walsh in the weeks after the February premiere (and a scan of that first edition is available as IMSLP #71438), but this elaborate keyboard part for Vo far guerra materialized only in a later printing (with a new title page Arie dellopera di Rinaldo, apparently June 1711).

What originally prompted me to look at all of this for this post was finding a seminar paper I had written in graduate school that was comparing these keyboard passages with those found in Handels organ concertos, essentially arguing that all of this could easily be cobbled together from the figuration of Handels other bravura works.  (Ive scanned some of my examples for that paper here.)  Now the glaringly obvious problem with my thesis is that all of my Handel examples post-date these Rinaldo performances by at least two decades; I picked the wrong music for comparison.  Handel had written a concertante part for organ in his Il trionfo del Tempo e del Disinganno (Rome, c. 1707), but its not all that much like the published Rinaldo solos; the closest comparison would be his Sonata for Harpsichord with Double Keys (HWV 579), which Terence Best dates to c. 1707-08 [p. 125].  Best argues that BWV 579 has no connection with Walshs Rinaldo realizations.  In that the text is different, Best is correct; but the similar figuration at least shows that Handelian origins of the latter are plausible.
SOURCE:  cropped scan of the beginning of HWV 579 as given in HHA Ser. IV Bd. 6, p. 80
There is no reason to assume that Handel ever notated the Rinaldo cadenzas; particularly as he apparently had no professional relationship at this time with the publisher, John Walsh, it is much more likely that another hand supplied these keyboard passages.  The scribe seems to have been William Babell (c. 16901723), who would have heard Handels original performances at first hand, as he was a violinist in the Kings Theatre where Rinaldo was produced.  Babell was much more widely known in his short life as a keyboardistindeed, this reputation was strong enough that Johann Mattheson would cite him in 1739 as possibly the greatest organist of the age.  Here is the relevant bit of Matthesons Der Vollkommene Capellmeister (as translated in Deutsch):
SOURCE:  cropped scan of Deutsch, Handel:  A Documentary Biography, p. 485, with a portion of Mattheson.
Even though Mattheson never heard Babell, this is a remarkable praise.  It is known that he studied with Johann Christoph Pepusch in London; that he studied under Handel is not certain, but he was clearly in Handels circle.  Moreover, in 1717 Walsh published his Suits of the most Celebrated Lessons Collected and Fitted to the Harpsicord or Spinnet by Mr. Wm. Babell with Variety of Passages by the Author.  This was a tremendously successful publication, and remained in print (from one pirated edition or another) throughout the eighteenth century.  Note the last item in the table of contents:
SOURCE:  cropped from (incomplete) scan available at archive.org.  A complete monochrome scan is available at IMSLP #279417.
The Vo far guerra in the Suits of Celebrated Lessons is considerably more elaborate than that published in Arie dellopera di Rinaldo a few years prior.  Graham Pont has probably devoted more attention than anyone else to the Handel/Babell connection, with several intriguing articles published over two decades.  From the first of these, he has contended that the substance of the harpsichord elaborations were Handels rather than Babells (and in subsequent articles he demonstrates that there were a number of copies of this made by people close to Handelalthough he also shows that the text kept changing).

We thus have several different versions of the keyboard cadenzas (for lack of a better word) for "Vo far guerra," from the rather tame but still dramatically intrusive version that Walsh published in about 1715 (and which has become the main text of the HHA, tacitly presenting it as the work of Handel himself) to the wildly fantastic version Babells Suits that was surely never intended for operatic performance, but rather uses Vo’ far guerra as the medium for a solo keyboard showpiece.  Chrysander published itor one version of itin HG vol. 48, and it must be some of the most visually-stimulating pages in the whole of that monumental edition:
SOURCE cropped from IMSLP #18931 scan of HG vol. 48, p. 242 ; but there's much more where this came from.
Gotta love that beaming!

If the original aria wasnt audacious enough, this blows it out of the water completely, with a variety of special effects.  (Peter Holman, in a fascinating article that posits that Babell rather than Handel should get the credit for the first English keyboard concerto, characterizes Babell's music as a mixture of boldness and limited compositional technique; from my limited exposure to it, I have to agree.)  There are remarkable moments, to be sure.  Consider this compelling crescendodecrescendo effect, achieved by a thickening and subsiding of the texture:
SOURCE:  ibid., p. 239
Perhaps this conveys some element that originated with Handel.  (Perhaps.  I doubt it.  There is nothing else I know from his pen that is remotely like this.)  If so, I suspect that Babells audaciously over-extended cadenza strings together ideas that Handel might have used in different performances of Rinaldo, not ever intending them to go together, and connected by who-knows-what.  Another speculation occurs to me:  maybe Handel did not conduct all the performances, and Babell (who must have been the finest keyboard player in the orchestra) took over for the harpsichord solos, later reworking his ideas from those extemporizations into the work that was eventually published as a lesson.   (For a fine recording of Babells lesson, you cannot do better than Erin Helyard’s.)

For one more audacity, René Jacobss 2003 recording of Rinaldo (Harmonia Mundi HMC 901796.98) turns to the Babell lesson for inspiration for the harpsichord solos of “Vo’ far guerra” (starting about two minutes in).  I think this choice absolutely spoils the dramatic momentum that ends the actor rather, it redirects all attention to the pit.  (Forty-five percent of this track is taken up just by the cadenza after the singers last cadence.) I think this decision is a serious mistake, but I concede that at least
  1.  it makes the da capo different than the first time through, 
  2.  maybe this shifting of attention does less damage on a recording than a live performance, and 
  3.  it is audaciously well played.