Reconstruction of unfinished Beethoven Trio in F minor

First movement, Unv 10 (Biamonti 637)

Beethoven composed many more piano trios than the eleven pieces that were published by Breitkopf und Härtel: the Gesamtausgabe by Breitkopf und Härtel turned out to be far from complete. Many pieces, including quite a few piano trios, were only rediscovered in the 20th century and published recently. 

In addition to the 11 piano trios, the following pieces are numbered randomly:

• No. 12: Trio in E-flat major for Violin, Cello and Piano Hess 48 Unv 9 from 1790-1792:
• No. 13: Trio in E-flat major for Clarinet, Cello and Piano Opus 38 from 1802, adaptation of the Septet in E-flat major Opus 20;
• No. 14: Trio in D major Violin, Cello and Piano Opus 36A, adaptation of the Second Symphony in D major Opus 36 by the composer, although the name Ferdinand Ries has also been mentioned;
• No. 15: Trio in E-flat major for Violin, Cello and Piano Opus 63, adaptation of the String Quintet No. 1 in E-flat major Opus 4;
• No. 16: Trio in G major for Flute, Bassoon and Piano WoO 37;
• No. 17: Trio in E-flat major for Violin, Cello and Piano Hess 47, adaptation of the first part of the String Trio No.1 in E-flat major Opus 3 from 1794-1795;
• No. 18: Trio in D major for Violin, Cello and Piano Anhang 3, which nowadays is attributed to his brother Kaspar Karl van Beethoven and probably dates from 1800 or before.
• No. 19: Trio in B-flat major for Violin, Cello and Piano Hess 50 and unfinished, probably from 1790.
• No. 20: Trio in F minor for Violin, Cello and Piano Unv 10 from 1816, which, for the sake of convenience, we will call trio no.20.

So, the whole piano trio story is a bit of a ꞌmessꞌ, unfortunately created by the erroneous sequence in the Breitkopf und Härtel Gesamtausgabe. However, the sequence listed above continues to be used, because, over time, it has become so accepted that we will never be able to change the sequence. We see that writing piano trios was an important musical form that Beethoven continued to practice a lot.
The composer probably stopped working on the Piano Trio in F minor Unv 10 in favour of the Piano Sonata No.28 in A major Opus 101, to focus on the sonata. Why Beethoven did not finish the piano trio is unclear. It could be because of the difficult negotiations with the publishers, illness or the quarrel with his cousin Karl, which meant that Beethoven was a little pressed for time and decided to focus on the Piano Sonata No.28 in A major Opus 101, which was already closer to completion.
A large part of the sketches is included in the so-called Scheide sketchbook, which Beethoven used until about May 1816, but he continued to work on the piano trio in the summer until the early autumn. In that period, the composer also designed the score of the first part with a total of 151 bars. Cees believes that the composer worked on both pieces at the same time, in light of the striking similarities, and in particular the similarity in the second part of the Piano Sonata No.28 in A major Opus 101. The similarities in particular involve the motif that we see from bar 19 onward and that is also harmonically reflected in the piano trio. Both in the piano sonata and the piano trio, the motif is worked out rhythmically and harmonically in virtually the same way. In both cases, the way it is used elsewhere is striking: in the piano sonata, the motif keeps recurring in the elaboration of the march theme, section B, and in the piano trio, it is elaborated even further, while also playing an important role in the main theme of the exposition.
Almost no sketches were left of that second part, or of parts three and four, but based on the extensive first part, we can conclude that Beethoven wanted to surpass the Piano Trio No.7 in B-flat major Opus 97 in size as well as sound. Cees believes that, even as a piece with one part, the new piano trio is a beautiful addition to the existing wealth of piano trios that the composer gave us.