Peter Kastner was one of those numerous up and coming young actors who came of age in the mid to late 1960s. He starred in several films, including one of Francis Ford Copolla's earliest legitimate efforts, "You're a Big Boy Now," as well as the hip "B.S. I Love You."
He had extensive TV work on a number of soap operas, and as the star of the outlandish, short lived "The Ugliest Girl in Town," about a cross-dressing model making it in Swinging London.
He later went on to become a successful director.
Kastner recorded a few sides for Colgems, and while they weren't successful, they are highly listenable, like "I Just Can't Get Over You," which is included at the link below.
(By the way, in the photo, Kastner is in the middle.)