Except for the last coda, the piece can be played on a 61 key keyboard. The last coda contains a single low A octave in the starting of the second repetition of the theme. And, there are the arpeggios, and the subsequent chromatic scale at the end... read more
Yes you can play Für Elise, but negative on the Moonlight Sonata. I would suggest a 76 key keyboard. They're next up from the 61. read more
I can't think of any piece going above the D below the highest C though, so you can probably play all Beethoven on a 76 key, since the 76 keys seem to have the E. Bach and Mozart and others coming before Beethoven had less keys to work with and you can play all their music too. read more