Who sang male back-up on the 1969 original of "Someday We'll Be Together" by Diana Ross and the Supremes?

Johnny Bristol. He also produced the record.

He had a disco hit of his own in the seventies. I think it was 'Hang On In There, Babay'.

Story about 'Someday' was that Johnny's vocal was supposed to be erased--he was in the booth because Diana was tired and he was encouraging her with all those "sing it pretty's," etc., but it came out so good that Gordy left him on. I find it the height of irony that he's in the background but Mary and Cindy aren't, on a record called 'Someday We'll Be Together' that was the farewell single for the group.

The Adantes and Johnny Bristol