Graffiti Rock with Run DMC
All right -- this is why I love YouTube.
This is from the pilot of "Graffiti Rock" -- a show that was supposed to become the Hip Hop American Bandstand or Soul Train.
It wasn't picked up -- but this clip has Run DMC from 1984.
Special extra: A young Vincent Gallo (of Brown Bunny infamy) makes a cameo at the beginning, introducing himself as "Prince Vince" and Kool Moe Dee and Special K from th Treacherous Three show up to battle at the end of the clip.