Listen to Biff's World / 27th Floor (From “Back To The Future Pt. II” Original Score) online. Biff's World / 27th Floor (From “Back To The Future Pt. II” Original Score) is an English language song and is sung by Alan Silvestri. Biff's World / 27th Floor (From “Back To The Future Pt. II” Original Score), from the album Back To The Future Part II (Original Motion Picture Soundtrack / Expanded Edition), was released in the year 2015. The duration of the song is 2:08. Download English songs online from JioSaavn.