Complex sentence: It was first sung by Harry Richman in 1930 and became a no.1 hit, and in 1939, Clark Gable sang it in the movie "Idiot's Delight".
Split into simpler sentences: It was first sung by Harry Richman in 1930 and became a hit. In 1939, Clark Gable sang it in the movie "Idiot's Delight".