Starting out as a touring musician after graduating from Harvard University, Brock has been a back-up singer for Linda Ronstadt, Karla Bonoff, and Andrew Gold. He was a staff producer for Quincy Jones and has written and produced hits for such artists as Christina Aguilera, Céline Dion, The Pointer Sisters, and Aretha Franklin. With Andrew Gold, he produced such hits as Lonely Boy and Thank You For Being a Friend (theme for The Golden Girls).