This refers to the first Playboy Jazz Festival in Chicago. The first American indoor jazz festival, produced in 1959, drawing more than 70,000 fans for five shows over three days between August 7th and 9th.
The three-day event saw Dizzy Gillespie, Dave Brubeck, Ella Fitzgerald, Kai Winding, Miles Davis, Count Basie, Jimmy Giuffre, Oscar Peterson, Louis Armstrong, Duke Ellington, Sonny Rollins and many more. It would be 20 years before Playboy would host another such festival.