Question: Which singer was the leader of an alternative rock band,  Bob Mould or Hayley Williams?
Sentence (from "Bob Mould"): Robert Arthur Mould (born October 16, 1960) is an American musician, principally known for his work as guitarist, vocalist and songwriter for alternative rock bands Hüsker Dü in the 1980s and Sugar in the 1990s.
Relevant evidence: Yes