Crossword puzzle clue "track mix for a party and what the five longest across answers comprise"

Track mix for a party, and what the five longest Across answers comprise

Legislation signed 6/22/1944 by FDR ... and, initially, what the nine longest across answers in this puzzle comprise

School's underclass team ... or, initially, what the four longest answers in this puzzle comprise

"Old MacDonald" refrain, and a feature of the five longest Across answers

Doctor's self-employment, and a hint to the starts of the five longest across answers

Gorilla in the midst of the five longest across answers

Bed found in the five longest Across answers

Field frequenter found in this puzzle's five longest Across answers