Wolfgang Amadeus Mozart : Sonata in C (1st movement)
You might think that this was an early work composed by the young Mozart, but it was actually composed later in the composer's short life as a simple work for young pianists. More piano sonatas and "fantasies" are vailable from Sheet Music Plus (US) or The Music Room (UK).
If you can't see music above, then install the easy to use Scorch Plug-in from Sibelius software.