He was born Luigi Francisco Varlaro in New York City. Cornell got his start with trumpeter Red Nichols and big band leader Sammy Kaye before going solo. He sold over 50 million records. Among his hits were "It Isn't Fair," "I'm Yours," "I'll Walk Alone," and "Hold My Hand." In 1993, he was inducted into the Big Band Hall of Fame.
He died in Aventura, Florida of advanced emphysema and diabetes.