Musical stars

Big-name stars lined up to make guest appearances. Stevie Wonder and Grover; Loretta Lynn and the Count; Smokey Robinson and a marauding letter U. "Sesame Street" also showcased Afro-Caribbean rhythms, operatic powerhouses, Latin beats, Broadway showstoppers, and bebop.

Now, after 4,526 episodes, the legacy is evident: It impacted the music world as much as it shaped TV history, inspiring fans and generations of artists.