Song Titles was a game played in both the British and American editions of Whose Line.
The British version involved three performers acting out a scene with the constraint that they could only speak in song titles.
In the American version, the format was more in line with that of Questions Only. This version was often rather challenging for the host. In one situation, Drew Carey buzzed one performer out for quoting a lyric rather than a song (which was incorrect, as the words used were in fact the song title) and subsequently allowed a song lyric to be quoted rather than a song title.