The Baroness Ertmann was an excellent performer on the pianoforte, and is said to have been unrivalled as an interpreter of Beethoven's music. Mendelssohn met her at Rome in 1831, and in a letter describes her playing of the C sharp minor and D minor Sonatas. We must now turn to the sonatas, yet neither for the purpose of analysis nor of admiration. We shall briefly discuss how far Beethoven worked on the lines established by his predecessors, and how far he modified them. And, naturally, the question of music on a poetic basis will be touched upon. The number of movements of which Beethoven's sonatas consist varies considerably: some have two, some three, others four. The three very early sonatas dedicated to Maximilian, Archbishop of Cologne, have only three movements (the second opens with a brief Larghetto, which, however, really forms part of the first movement). But the four Sonatas Op. 2 (Nos. 1, 2 and 3) and Op. 7 all have four movements--an Allegro, a slow movement, a Scherzo or Minuet and Trio, and a final Allegro or Rondo. There are examples in later sonatas of similar grouping; but it is an undeniable fact that in some of his greatest sonatas--Op. 31 (No. 2), Op. 27 (No. 2), Op. 53, Op. 57--he reverts to the three-movement sonata so faithfully adhered to by Emanuel Bach, Haydn, Mozart, and Clementi. And there is evidence that the omission of the Minuet or Scherzo in Op. 10 (Nos. 1 and 2), in Op. 13, and in others named above, was the result of reflection and not caprice. Among sketches for the Sonatas, Op. 10, Beethoven writes: "Zu den neuen Sonaten ganz kuerze Menuetten" (to the new sonatas quite short Minuets); and also, a little further on, "Die Menuetten zu den Sonaten ins kuenftige nicht laenger als von 16 bis 24 Takte" (in future the Minuets to the sonatas not to exceed from 16 to 24 bars). Then, again, there are two sketches for a movement of the Minuet or Scherzo kind, which were almost certainly intended for the Sonata No. 1 in C minor. One of these was afterwards completed, and has been published in the Supplement to Breitkopf & Haertel's edition of Beethoven's works. Both these were finally rejected, yet Beethoven made still another attempt. There is a sketch for an "Intermezzo zur Sonate aus C moll," and at the end of the music the composer writes: "durchaus so ohne Trio, nur ein Stueck" (exactly thus without Trio, only one piece). So the Minuets were to be short; then the limit of length is prescribed; and, lastly, an Intermezzo _without_ Trio is planned. The composer proposed, but his [Greek: daimon] disposed; the Sonata in C minor finally appeared in print with only an Adagio between the two quick movements.