Interstella 5555: The 5tory of the 5ecret 5tar 5ystem (2003)

What it's about

Four talented alien musicians are kidnapped by a record producer who disguises them as humans. Shep, a space pilot in love with bass player Stella, follows them to Earth. Reprogrammed to forget their real identities and renamed The Crescendolls, the group quickly becomes a huge success playing soulless corporate pop. At a concert, Shep manages to free all the musicians except Stella, and the band sets out to rediscover who they really are — and to rescue Stella.