confidence." Cellist Steven Isserlis described the work as the first cello sonata in history to give the two instruments equal importance. It has remained a model in the genre, for works by Mendelssohn, Brahms, Debussy and Shostakovich. Structure and music The sonata is structured in three movements, with an 18-bar slow introduction to the third movement: Allegro ma non tanto Scherzo. Allegro molto (in A minor) Adagio cantabile – Allegro vivace Beethoven noted on the autograph manuscript "Inter lacrymas et luctus" (Amid tears and sorrows). However, the work's character has been described as "positive in attitude", and "radiating serenity, humour and joy", similar in mood to some works by Franz Schubert. The sonata is a classical work with measured proportions and elements of symmetry. Throughout the composition, the two instruments are treated as equal partners, not as solo and accompaniment as in the early cello sonatas. Allegro ma non tanto The first movement is in alla breve time and marked Allegro ma non tanto (fast but not too much). It is written sonata form, and opens with an expansive melody introduced by the cello alone. Beethoven composed an opening by the string instrument alone also as a feature in violin sonatas. The piano then enters with cadenza-like flourish, which leads into a repetition of the opening theme played in octaves by the piano. The melody consists of several motifs to be used as material for further development. A bridge passage follows, leading to a second subject played, as John Mangum noted, in "organic relationship" with "the cello and piano interweaving, each gently decorating and elaborating the other's part". The development gives greater emphasis to the first theme. In the recapitulation, the first cello is accompanied by running triplets of the piano. One of the motifs is similar to the first motif in Bach's aria "Es ist vollbracht" (All is fulfilled) from his St John Passion, introduced there by the viol. It is unclear if the similarity is intended, but would match the inscription "inter lacrymas". The movement has moments of stillness and introspection both before the recapitulation and before the "final flourish". Allegro molto As in some of Beethoven's piano sonatas, there is no slow movement. The second movement is a scherzo in the tonic minor, A minor, with a contrasting trio in A major; the scherzo is played three times, alternating with the trio played twice. The scherzo makes