This is not a joke, but something real, as told by Danish saxophonist Jesper Thilo in his autobiography:
<<Duke’s orchestra was in town (Copenhagen, Denmark). Jesper’s phone rang:
“ Duke wants an alto sax for the band tonight”.
Jesper was thrilled:
“Great, he said, I’m coming right away”.
“Don’t bother to come, just send the saxophone with a taxi”. >>