You don't ever get a chance to play what you really do; and if you do, you notice that you can't play, because you haven't been. And often I'd be asked to play like somebody else, like Joe Sample. I'd say, "I can't play like him. He's an original." I'd be asked to try and the producers would love it, but I'd feel rotten. Then one time I ran into Joe and he told me, "Man, I'm tired of people asking me to play like you." My jaw dropped. Then I found out this is a common practice.

On his years in the studio, playing on films, TV shows and jingles, as quoted in "He Arranges, Composes, Performs: Fischer, A Renaissance Man Of Music"

He Arranges, Composes, Performs : Fischer: A Renaissance Man Of Music - latimes[latimes.com]