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.
Fred Green is his preferred name
we do not know his preferred nickname or name