What was Benjamin Linus playing on the piano in Lost (Season 4)?

Question

In episode 10, I think it was 'The Shape of Things to Come', Ben was on the piano near the start.

Was it a song that he just made up or was it an actual song?

Because, my brother thinks I should learn it. Apparently Benjamin Linus made piano's cool....

Answer 1

it was episode nine

the song was prelude in c sharp minor. it was by some russian guy whos name i dont know