What was the song that Robert Pattinson played to Kristen Stewart in movie twilight by claude debussy?

The song Robert Pattinson plays to Kristen Stewart in the movie Twilight is not by Claude Debussy.

The song is actually "Bella's Lullaby" by Carter Burwell, who composed the score for the movie.

It's a beautiful, haunting melody that perfectly captures the mood of the film.