Which movie uses this piece of music? I thought it was Cloud Atlas or 2046, but the details on their IMDB pages are scarce. I could swear it sounds familiar.
Recent films that featured this piece, according to IMDb:
Il Divo (2008)
Mr Nobody (2009)
Ice Castles (2010)
Royal Flash (1975)
Monster Club (1981)
Your question might not stay here for long, though. Questions that generate lists are considered off-topic and ID questions must include sufficient details about the movie you're looking for.