[music] One last point before diving into the sonata: a prominent feature of many late period works is the way in which they simultaneously look back, and point the way to the future. The Diabelli Variations reference Bach obliquely, and quote Mozart directly, but they also contain music that anticipates Schumann and even Chopin. The Sonata Opus 110, with its ariosos and fugues, owes much to the baroque, but its sonority is arguably the most romantic of any of the sonatas. And the final string quartet, the Opus 135, is probably the most Haydnesque of all of Beethoven’s quartets, even though its literary, programmatic last movement, which strives to translate words into tones, was surely an inspiration to many 19th and 20th century composers. The Sonata Opus 101, similarly, is a forward AND back piece. Its brief slow movement, much like Opus 110’s, sounds very much like a baroque arioso dolente, and there is a fully fleshed-out fugue in the finale. But this was also one of Beethoven’s most influential pieces, and Mendelssohn and Schumann, in their own very different ways, both paid homage to it. I’ll play the exposition of the first movement in just a moment, but first I want to play just the very opening, followed by the opening of Mendelsohn’s Sonata in E major. So, the Beethoven [music] And now, the Mendelssohn. [music] I think there can be no argument that the Beethoven is the point of reference for Mendelssohn here. In both cases, the short-long, short-long rhythm predominates, and both works even begin on the same notes, seemingly in the same key. But Mendelssohn – and I say this with ultimate respect, for despite the ever-so-slightly condescending way he tends to be viewed now, he was a composer of great depth, perhaps the greatest child prodigy in the history of music, and the most erudite and cultured of all of his peers – Mendelssohn has completely missed the ultimate point of the Beethoven. For while both works begin on an E major chord [music], only the Mendelssohn sonata is actually in E major; in the case of Beethoven, the E is quickly revealed to be the dominant of A major. [music] Now, this is not an entirely unprecedented move. In one famous example, Beethoven’s 1st Symphony, the C major, it doesn't even begin in C major [music] – instead, the chord we begin on is the relatively obscure 5-7 of 4. [music] But within a few moments, the home key has been established, and really, this opening is a prank – a Haydn-ish wink at the audience. But while in the 1st Symphony, harmonic stability is quickly achieved, and then maintained, in Opus 101, it proves hugely elusive. Let me now play the entire exposition. [music] That is the entirety of the exposition – this movement is possibly the most radical of the piece, and it's deeply wonderful, but it's short. The scope of this sonata seems modest at first, and then is constantly expanding. Anyway, to return to the previous topic, the work begins as if in mid-sentence. This is partly a question of sonority – Beethoven used the word “reveries” in describing this sonata, and the opening, to me at least, evokes the feeling of being half-asleep, caught between reality and the world of dreams. But really, again, the main cause of our feeling that we are joining the work when it is already in progress is Beethoven’s refusal to land firmly in A major. There is no real ambiguity about the tonality – we understand, before the end of the first phrase, that this must be A major. What else could it be? [music] Wants to go here: [music] But the key is defined, not by its presence, but by its absence, and we spend the whole movement in search of it.