Spot on, Hollowfox! I was traveling through southern California in the summer of 1962 (I think) and heard the live broadcast of the T.A.M.I. show on the radio. Little Stevie Wonder drove the crowd wild with what became known as "Fingertips, Part 2".

If you ever listen to the recording of that tune, pay attention to a place in the middle where Stevie made a false exit. He returned to the stage and we hear the piano and bass attempted to reprise the tune. Meanwhile, another group was headed onto stage because they thought Stevie was done. Once they were onstage, they didn't want to appear as if they had made a mistake. So they stayed and attempted to play along. You can hear one of them say, "What key? What key?" just before Little Stevie Wonder begins the rest of his number with "Mary Had A Little Lamb" on the harmonica.

(I have never learned the significance of T.A.M.I. - does anyone know for sure? I only know that it was a "benefit" show.