Canada's Pete Best
You could say that Chad Allan is the unluckiest guy in show business. He left The Guess Who and three years later, they started having huge hits with Burton Cummings as their new lead singer. Then, he joined Brave Belt, a group with Randy Bachman. After he left that group, it renamed itself Bachman-Turner Overdrive (BTO).
It's too bad because, despite this run of musical bad luck, Mr. Allan is a genuinely nice guy. (He was a friend of my family briefly during my teen years and he would play new songs for me in a futile effort to discover if they would appeal to teenagers. "Futile" because at the time I wasn't listening to much music recorded after 1965.)
In this online interview, Mr. Allan discusses the mystery that stumped record listeners and led to the Guess Who's first big hit, as well as other tales of the earliest days of "The Guess Who?".