I was wondering if anybody knew the two main pieces that are played throughout the film
thanks :)
'It makes you wonder how many things exist just because people believe in them'
Schubert: Piano Trio No. 2, E Flat.
Rachmaninov: Prelude Opus 23, No. 5, G Minor.
Not sure about Schumann.
The main one that keeps recurring is the Scherzo from Schubert's Piano Sonata No. 20 in A major: http://en.wikipedia.org/wiki/Schubert%27s_last_sonatas (Walter first plays it in the recital near the beginning, after talking with Erika about Schumann's craziness.)
I'm not sure which the second one you mean is, but the one playing during the extended lesson scene with Walter (where Erika discusses his dynamics and where he asks to kiss her neck) is the Andantino (slow movement) from the same sonata.
The piece her student plays with the singer is "Im Dorfe" ("In the Village") from Schubert's Winterreise: http://en.wikipedia.org/wiki/Winterreise (Fitting lines: "Ich bin zu Ende mit allen Träumen. / Was will ich unter den Schläfern säumen?" "I am finished with all dreaming / Why should I linger among sleepers?")
Otherwise, the Schubert Trio is what they play in rehearsal (where the violinist asks to change the direction of the trill); the Rachmaninoff prelude is only played briefly in the montage during Walter's recital audition.