Hess 37. Transcription of Mozart’s Fugue for Two Pianos, K. 426, for string quartet (two pianos?) n.d. Hess 37.

This copy was identified by Hess as a transcription for string quartet and was therefore assigned a number: Hess 37. The pages of this copy were scattered across the world; today pages 1–2 and 5–6 are in the Robert Owen Lehman Collection at the Pierpont Morgan Library in New York, while pages 3–4 are held at the Beethoven-Haus in Bonn. In the musical example you can hear Mozart’s part as copied out by Beethoven (hence we continue to describe the piece as “for two pianos”).

Fugue by W. A. Mozart, KV 426. Beethoven transcribed this work in score. See also the reference made by Otto Jahn in Mozart, by Hermann Albert, vol. 2, Breitkopf & Härtel, Leipzig, sixth edition, 1924, p. 158. Unpublished. No further details are known.

[It appears that Hess accepted this number in its entirety, because of the Jahn–Albert reference, purely for reasons of convenience. A closer examination of the original manuscript (now partly at the Beethoven-Haus in Bonn and partly in the Robert O. Lehman Collection at the Pierpont Morgan Library in New York) reveals that it is in fact a copy, made by Beethoven, of the original version for two pianos of Mozart’s Fugue KV 426, which had been transcribed for string orchestra by Mozart himself (KV 546). It is widely held that Mozart wrote KV 546 for string quartet rather than for orchestra; however, Mozart’s annotation “bassi” (in the plural) clearly refers to an orchestra, not to a quartet. See the Eulenburg edition no. 369, or Alfred Einstein, Mozart: His Character, His Work, Oxford University Press, Oxford–New York, 1962¹⁸, p. 273.

In practice, Hess catalogued—among the works for string quartet—a copy made by Beethoven of a Mozart work originally for two pianos (KV 426), because he believed it to be Mozart’s version for string quartet (KV 546). The manuscript has not been dated with certainty, but it is possible that Beethoven studied it while working on Op. 134, which was originally a fugue for string quartet and which he later transcribed for piano four hands. [The transcription of Op. 134 is also catalogued as Hess 86.]

There are 36 minor discrepancies between Beethoven’s copy and Mozart’s original; most are pen slips, although many could be regarded as “improvements” by Beethoven. This is not the only work by Mozart that Beethoven copied. There is another at the Pierpont Morgan Library which is a “fair copy of the final bars of the finale, probably not copied before 1790,” of Mozart’s String Quartet in A major, KV 387. See The Mary Flager Cary Music Collection, Pierpont Morgan Library, New York, 1970, p. 17. Richard Kramer maintains that “the copy of KV 387 can be dated between 1799 and 1800.” Portions of KV 387 are also held at the Beethoven-Haus in Bonn, catalogued as NE 119. Beethoven also copied the Andante from Mozart’s Quartet KV 464. That autograph is now at the Stiftelsen Musikkulturens Främjande in Stockholm. See Richard Kramer, “Das Organische der Fuge: On the Autograph of Beethoven’s String Quartet in F Major, Opus 59, No. 1,” in The String Quartets of Haydn, Mozart and Beethoven: Studies of the Autograph Manuscript, Harvard University Press, Cambridge, 1980, pp. 230–31.]