This category includes groups, right? Here's 2 of the best--one is familiar, the other obscure.
The Magnificent Men--a Philly-based essentially doo-wop group that just missed the big brass ring. Here's some stuff:
From back in the day: and
Everything they are:

Three Dog Night
Barrage me if you like but don't deny TDN their due--soulful voices and champions for unheard (at the time) writers: << damn shame he went over the edge with that powder. << fortunately he made it most of the way back.
The remaining 2 guys with a cracker-jack ork behind them: << Like the Edmonton Symphony, they are a split group--playing serious orchestral music one day, swinging with a pop bunch the next [one of Ray Charles' better later perfs is with the ESO--worth your time to see/acquire]. OK no more teasing--here's the whole thing: