Three Headed Broadway Star (or Three Headed Song) was a game played on the American edition of Whose Line.
The premise was that the three performers were all part of the same Broadway star and would perform a "hit love song" from a "new Broadway musical", with both the musical and song titles being decided by the audience. Each performer would sing a word of the song each.
The game had often featured Drew Carey. In his intial appearances, Drew was unable to keep to one word, often singing entire lines. American series 3 introduced the idea of singing the song to an audience member, although this was largely cosmetic.
While the songs all nominally made sense, most featured unusual grammatical constructions, as well as Colin Mochrie's reliance on strange words with no real rhyme. Repetition was also used for comic effect, such as the constant use of the words "Jello" and "Puddin'" in one song, as well as Wayne Brady's over-use of the word "abyss" and Colin's use of the word "You" repeatedly (9 times consecutively).