Question: Who is the lead singer of doobie brothers?
Disambiguated questions and answers: question: Who is the first lead singer of doobie brothers?
Who is the second lead singer of doobie brothers?
Who is the third lead singer of doobie brothers?
answer: Johnston
Tom Johnston
Charles Thomas Johnston
Michael McDonald
Johnston
Tom Johnston
Charles Thomas Johnston
Natural Questions answer: Tom Johnston
Michael McDonald (from the Wikipedia article "The Doobie Brothers")