Conversation so far:
Why did Frank Sinatra have a career slump?
Both of Sinatra's films Double Dynamite (1951), an RKO Irving Cummings comedy produced by Howard Hughes, and Joseph Pevney's Meet Danny Wilson (1952) failed to make an impression
What was Frank Sinatra's debut film?
Sinatra made his film debut performing in an uncredited sequence in Las Vegas Nights (1941), singing I'll Never Smile Again with Tommy Dorsey's Pied Pipers
Who was in the film Las Vegas Nights with Frank Sinatra?
Sinatra made his film debut performing in Las Vegas Nights (1941) with Tommy Dorsey's Pied Pipers
Was Las Vegas Nights a musical film?
Yes, Sinatra sang I'll Never Smile Again with Tommy Dorsey's Pied Pipers
Did Frank Sinatra have other musical films besides Las Vegas Nights?
He had a cameo role along with Duke Ellington and Count Basie in Charles Barton's Reveille with Beverly (1943), making a brief appearance singing Night and Day“

Question: did anything interesting happen to him during 1941-1952?
Self-contained rewrite: Did anything interesting happen to Frank Sinatra during 1941-1952?