Pre-Code Hollywood

Hellzapoppin' (1941) Olsen and Johnson, a pair of stage comedians, try to turn their play into a movie and bring together a young couple in love, while breaking the fourth wall every step of the way. Zany comedy that pioneered many concepts used in many Hollywood classics (funnily enough, many Hollywood producers would try to pretend they invented things that were actually ideas pioneered in this movie). Incidentally, the lindy-hop dance performance (the scene with the black workers dancing acrobatically together) set the standard for professional lindy-hop dancers, and is still used to teach professional dancers today.