Question: When was the hip hop group formed in which Melvin Glover was a  pioneers of rap as lead rapper?
Sentence (from "Melle Mel"): Melvin Glover (born May 15, 1961), better known as Melle Mel and Grandmaster Melle Mel, is an American hip-hop musician – one of the pioneers of rap as lead rapper and main songwriter for Grandmaster Flash and the Furious Five.
Relevant evidence: Yes