Well, I recall - way back in the 60's - that there were two groups played on "black" stations who made the R&B charts regularly and they were the Righteous Brothers and the Young Rascals, or Rascals - if you prefer.

I'm sure there were others, like maybe The Reflections from Detroit with "(Just Like)Romeo And Juliet;" and the another white group (I believe from Detroit, too)whose name I can never rememer - they had a hit with, "Get Ready," sometime after the Temptations. Also, I think that Len Barry, following his departure from the Dovells, was also played on black R&B stations for his monster hit, "1 - 2 - 3."

A fun thread. I recall with fondness the many nights on the road back in my "band days" when we would pass the miles away playing music
trivia amongst ourselves while driving to the next gig - much fun. Cheers.