Beethoven's decision to publish three piano trios as his Op. 1- his calling card to the world - was a mark of his coming of age in his own eyes, but little is known about when he began writing them or when he finished them. When all three trios were played at Count Lichnowsky's palace, probably in 1793, Haydn praised them but advised Beethoven to hold off publishing the third one, which was the boldest (and most Beethovenian) of the set. Haydn thought that including it in Beethoven's first publication would be a bad career move, because it would be hard to understand and be badly received; Beethoven, who thought the third trio the best of the set, didn't want to hear Haydn's reasons, and ascribed his advice to jealousy or ill will. In fact, Haydn was predicting exactly what Beethoven would be hearing from critics for the rest of his life. But the trios, published in 1795, were a hit with the buying public: the next year, in advertising Beethoven's Op. 2 piano sonatas, the publisher mentioned the public's approval of Op. 1.

If the modernity or difficulty of the C-minor Trio was a problem for some, it must have been a revelation for others. Here was a new, important, and bold musical voice, with powerful things to say. From the very outset, it sets foot into the turbulent world that Beethoven would later explore in such works as the "Pathétique" Sonata and the Fifth Symphony. Seven notes into the first movement, the first theme suddenly moves up a half-tone. Shifts of a semitone introduce instability and tension, and often make for music that is impassioned and embattled. And while Beethoven does not use the device as memorably here as he would ten years later in the "Appassionata" Sonata, he does use it insistently in a movement of great urgency and power.

There is nothing urgent, or powerful, for that matter, in the second movement, a simple theme with five variations, or the following Minuet, both of which are marked by elegance and wit.

The furious, driving Finale returns to the intense mood of the first movement. Just as it seems to have settled finally into the home key of C minor in preparation for a big finish, it modulates down to B minor, in context the unlikeliest of keys and perhaps the biggest surprise of the whole Trio. Beethoven was fond of just-before-we-get-home detours (the sort of thing that critics found "strained and recherché"), probably because he had so much fun getting back on track. It is not the Trio's last surprise: the end itself is not what any listener is likely to expect.

- Lawyer and lutenist Howard Posner also annotates programs for the Salzburg Festival, among others.