Complex sentence: Christened Ann Veronica LaHiff in New York City, she began her acting career in Broadway musicals, but was a successful talkies actress because her musical background enabled her to play in the movie musicals of the 1930s.
Split into simpler sentences: Christened Ann Veronica LaHiff in New York City, she began her acting career in Broadway musicals. She became a successful talkies actress because her musical background enabled her to play in the movie musicals of the 1930s.