Here’s Rod Stewart as lead singer for Faces, backed up by The Memphis Horns, covering the Temptations’ “I Wish It Would Rain,” a live recording from 1973:
http://www.youtube.com/watch?v=0_ZBh5McHyM
It’s a surprisingly nice cover, different from the original as you’d expect. The comments section on YouTube is interesting reading, with a band member as well as several people who attended the concert commenting.