I remember this segment from around 1984 or so (Season 15?) Herbie Hancock was big deal, thanks to his "Rockit" video on MTV, so Sesame was quick to capture him while he was still a had a shelf life in pop culture. (Like Bobby McFerrin a few years later).
Herbie has been a jazz musician since the 60's, scoring movie soundtracks, jamming with Miles Davis, but still remained outside the mainstream.