"Xanadu" is the title song from the soundtrack album Xanadu, and is the title song from the 1980 film of the same name. A rare collaboration for ELO, the song is performed by the Electric Light Orchestra (ELO) and Olivia Newton-John. Newton-John sings the primary vocals, with ELO (Jeff Lynne) adding "parenthetic" vocals in the style of their other songs on the Xanadu soundtrack, along with providing the instrumentation. The single reached number 1 in several countries, and was the band's only UK number 1 single, when it peaked there for two weeks in July 1980. The song peaked at number 8 on the Billboard Hot 100 in the US. This was the first song beginning with the letter 'X' to ever chart on the Billboard Hot 100 and it remained the only one until 2000's "X" by Xzibit.