Tony Bennett

 was a singer famous for the song, "I Left My Heart in San Francisco". Jack Harkness met him at the party thrown in honour of Bennett's first Grammy Award. (COMIC: The Transformed)

Owen Harper and Diane Holmes once danced to his rendition of "The Good Life". (TV: Out of Time)

Behind the scenes
Though Bennett was not specifically identified by dialogue in Out of Time, he is easily identified by his unique voice and signature arrangement of "The Good Life".