Frederick “Dennis” Greene (January 11, 1949 – September 5, 2015) was an American singer who was a member of Sha Na Na who were formed in 1969 at Columbia University in New York as the Columbia Kingsmen. The name change to Sha Na Na occurred because of another group with a similar name, which was known for the song Louie Louie.
The television show Sha Na Na aired from 1978 to 1981. Greene choreographed most of the moves for the show, on which he was known simply as Denny. Denny was portrayed in the series as the most intelligent member of Sha Na Na. He sang lead in the song “Tears on My Pillow” when he appeared with Sha Na Na in the movie Grease, in 1978.