Question: The singer who contributed vocals to the track "You Know What It Is" was a member of what hip hop group?
Sentence (from "You Know What It Is"): "You Know What It Is" is a song by American hip hop recording artist T.I., released July 10, 2007, as the second single from his fifth studio album "T.I. vs. T.I.P." (2007).
Relevant evidence: Yes