The Monk Man
Two jazz-hipsters were at a nightclub listening to quartet session led by the pianist-composer, Thelonius Monk. When it came time for Monk to solo, the "master of cool" sat staring into space as the rhythm section wailed on.
"Hey man," complained a hipster, "he didnt play anything."
"Yeah," said the other, "but just imagine what he was thinking."
Fifties jazz joke, quoted in The Economist 4/11/98