Hampton, who was performing with his band in the White House East Room, demanded that the president, a long-time jazz fan and saxophonist, play a tune.
"We have one of the greatest saxophone players with us tonight," Hampton told Mr. Clinton. "And I want to hear you play sax."
Mr. Clinton picked up the instrument, tried a few bars with the piano, then launched into My Funny Valentine with Hampton's full orchestra.
The president then saluted Hampton's 90th birthday by presenting him with a cake, and leading the gathering in singing Happy Birthday.
Hampton, the "King of the Vibraphone," was born in Alabama in 1908. He got his first big break with Louis Armstrong in 1930, performed with Tommy Dorsey in 1936, and went on to form his own legendary band in the early 1940s.
Hampton still tours the world with his 17-piece orchestra and recently signed an exclusive recording contract with Mojazz, the new jazz division of Motown.