Conversation so far:
When did Sinatra debut?
Sinatra made his film debut in 1941, performing in an uncredited sequence in Las Vegas Nights, singing "I'll Never Smile Again" with Tommy Dorsey's The Pied Pipers.
When did he hit his slump?
The New York World Telegram and Sun ran the headline "Gone on Frankie in '42; Gone in '52".

Question: What musical films was Sinatra in?
Self-contained rewrite: What musical films was Frank Sinatra in?