Lena Horne first performed with Kermit in the early seventies on Sesame Street. She sang a poignant version of "Bein' Green". She returned to Sesame Street about five years later helping Grover overcome his shyness in the song, "How Do You Do". (This song was released on the 1979 album "The Stars Come Out on Sesame Street"). In this episode, she demonstrates her natural rapport with the Muppets, most notably in her scene with Gonzo. (thetvdb.com)