Number of guys to win gold with two voice parts

Number of guys to win gold with two voice parts: 5

Don Barnick = Grandma's Boys 1979, Keepsake 1992
Brian Beck = Dealer's Choice 1973, Side St. Ramblers 1983
Tony De Rosa = Keepsake 1992, Platinum 2000, MaxQ 2007
Gary Lewis = Platinum 2000, MaxQ 2007
Glenn van Tassell = Auto Towners 1966, Gentlemen’s Agreement 1971