⌂ Sonata K519 (Domenico Scarlatti)

This sonata has a generally serious (minor key) mood, but it explodes in a fantastic cadenza in major key. You should listen to Trevor Pinnock's recording (Deutsche Grammophon Galleria 463 220-2). Here's the plain score (Lilypond sources).

Thank to Lilypond's MIDI output capabilities, you can even get a MIDI file of this sonata, or (courtesy of Timidity) an Ogg Vorbis digital audio rendition (harpsichord ♩♫; piano ♩♫; organ ♩♫; concertina ♩♫; marimba ♩♫).