Lou Rawls (1933-2006) was an actor and R&B singer with a four-octave range. His notable hits from the 1970s include "You'll Never Find Another Love Like Mine" and "Lady Love."
Rawls made two guest appearances on Sesame Street, singing the alphabet in Episode 0043, and singing "I'm Not Afraid to Cry" in Episode 0631. According to the booklet for Old School: Volume 1 (which includes Rawls' alphabet song as a bonus feature), Rawls balked at the idea of using cue cards during the performance, only to change his mind when he forgot the order of the letters.
He was also the guest star on The Muppet Show episode 215, where he performed his hit "Groovy People."
Rawls sang many of the songs featured in the Garfield TV specials that aired on CBS during the 1980s and 90s, and also did voice work for Hey Arnold!, Jungle Cubs, and The Rugrats Movie.