What does the cryptic crossword clue "Room after musical for ‘70s rom-com (5,4)" mean?

The wordplay uses a charade (building blocks). ANNIE (synonym="“musical”") + HALL (synonym="“room”") = ANNIEHALL The answer is ANNIEHALL.

Room after musical for ‘70s rom-com (5,4)

Guardian Cryptic #29538 | 25 Across | 2024-11-12 flower