B. B. King (b. 1925) is a well-known blues guitarist and songwriter.
King said the alphabet on Sesame Street in Episode 0130 and appeared in Monster in the Mirror celebrity version.
He returned in Season 32 (2001), performing a song about the letter B with Bert, Benny Rabbit, Big Bird and Baby Bear. (EKA: Episode 3962)
He appeared in "Yakety Yak - Take It Back", a recycling PSA that eventually aired on Sesame Street.