Slow tempo as function of interest

Examining a typical, randomly chosen Allegro of a Mozart or Haydn quartet, sym- phony or sonata, will show that its fast notes, usually 16ths, although looking like 16th-notes in a „normal‟ fast movement by Bach, behave quite differently. The functional difference of these durations has been most aptly described by Joel Lester, who explains the difference between the old and the new style in that events of high complexity and density, capable of capturing the interest of the listener, occur in the music of Bach on smaller durational levels than in the Classical style.

In the Bach passage, on the other hand, the greater complexity of accentuation patterns at the fastest levels causes these fastest levels to become a possible focus of attention.[…] The tempo taken in this Bach prelude [A major, WTC II] largely determines whether the eighth-to- sixteeenth-to-thirty-second levels or the quarter-to-measure-to-two-measure levels receive the sharpest focus. Such a choice of focal points is possible in this piece because of interesting and complex features at many levels in the metric hierarchy. No listener would follow the eighths of the viola part at the opening of Mozart‟s Fortieth or in the melody at the beginning of Bee- thoven‟s Fifth the way he or she might follow the sixteenths and thirty-seconds throughout Bach‟s prelude. Hence, no listener would wish for a performance of these Mozart and Beetho- ven works at a tempo so slow that the eighth notes were brought into focus but the two- measure or four-measure units were so long that they would lose their unity.119

117 D. G. Türk, Klavierschule, 2/1802, 106: “A far more moderate tempo is generally taken for granted for an Allegro composed fifty years or more ago than for a more recent composition with the same heading.”, tr.by Sandra Rosenblum in her Performance Practices in Classic

Piano Music, 319. I am indebted to Professor Rosenblum for drawing my attention to this

passage.

118 Rosenblum, ibid., 318.

Lester has rightly sensed the fundamental difference between the fast levels of the Bach versus Mozart-Beethoven styles. He had only one step more to go, to show that the seemingly equal durational levels (16ths, or eighthnotes in allabreve) in these respective styles, although similar in ubiquity, do not play equal roles. The change of function of the 16th-note from the early to the late 18th century largely reminds one of the transformation of the fast stratum from Renaissance to Baroque; even though the older style revolution, on the threshold of the 17th century, was combined with a drastic change of notational practice, namely a nominal fourfold note-value reduction. The striking difference between the Bach and Mozart genera- tions is, at what durational level the “real action” takes place. It is remarkable that Lester‟s observation has at least one parallel in 18th-century musical thought, com- ing from a person who belonged to the close circles of J. S. Bach, Friedrich Wil- helm Marpurg, In his Anleitung zur Musik überhaupt und zur Singkunst, 1763 (p.70f):

[9*] Ob gleich die Bewegung des Tacts... von der Größe der Noten natürlicher Weise bes-

timmet, und z. E. in der zweytheiligen Tactart, derjenige Tact, wo jeder Tacttheil aus einer weissen [] besteht, langsamer als derjenige, wo jeder Theil nicht mehr als ein Viertheil en- thält, ausgeführet werden sollte: doch geschicht doch alle Augenblicke das Gegentheil. Die Ursache davon ist unter andern diejenige Eigenschaft jedes Tonstückes, vermöge welcher in selbigem mehr oder weniger Notenfiguren von verschiedener Grösse gebraucht werden; und vermöge deren dasjenige Tonstück, wo nur zweyerley Arten von Noten vorhanden sind, wenn sonst keine andere Umstände das Gegentheil erfordern, geschwinder ausgeführet werden kann und muß, als dasjenige, wo die Verhältnisse weit mehr vervielfachet sind. Diese Aufhebung des Verhältnisses zwischen der Art der Notenfiguren und der Tactbewegung hat die Musiker genöthiget, zur Bezeichnung der Grade der Langsamkeit oder Geschwindigkeit, gewisse italiänische Kunstwörter anzunehmen.120

What Marpurg describes here is the degree of rhythmic complexity, or rhythmic

interest, as an indicator of tempo, as mentioned by Lester. Furthermore, what Lester

only suggests as an analytic observation is given by Marpurg as a general prescrip- tion, or rule of performance practice (“geschwinder ausgeführet werden kann und

muß”).

How far then is one entitled to apply Lester‟s (and Marpurg‟s) fundamentally correct observation to performance tempo? It seems that the attempt to bridge the gap between harmonic analysis and performance is not infallibly accurate and can- not be considered mandatory, or logically compelling, in any particular instance. The reason for our uncertainty is the dialectical nature of the “complexity argu- ment”, as we shall presently see. Let us examine Lester‟s concluding remark:

“Hence, no listener would wish for a performance of these Mozart and Beethoven works at a tempo so slow that the eighth notes were brought into focus but the two-measure or four- measure units were so long that they would lose their unity.”

One should ask, precisely what tempo is so slow as to bring such figures into focus? We have already mentioned the Alberti-basses in slow movements of Mo- zart‟s piano sonatas, with tempi “dangerously” near to bring the background figures into main focus; but this hardly happens in “conventionally satisfactory” interpreta- tions.121