Complex sentence: Billy Williams (December 28,1910--October 17,1972) was an African-American singer, who had a successful cover recording of Fats Waller's "I'm Gonna Sit Right Down And Write Myself A Letter" in 1957.
Split into simpler sentences: Billy Williams (December 28,1910--October 17,1972) was an African-American singer. He had a successful cover recording of Fats Waller's "I'm Gonna Sit Right Down And Write Myself A Letter" in 1957.