From Wikipedia:

Deadman's Curve is a 1978 made for TV film based on the musical careers of Jan Berry and Dean Torrence. Developed from a 1974 article published in Rolling Stone magazine by Paul Morantz, who also helped write the screenplay.

Cast:

    Jan Berry: Richard Hatch

    Dean Torrence: Bruce Davison

    Annie: Pamela Bellwood

    Dr. Vivian Sheehan: Floy Dean

    Susan: Denise DuBarry

    Billy: Kelly Ward

    Bob "The Jackel" Smith: Wolfman Jack

    Rainbow: Susan Sullivan

Also features cameo appearances by Dick Clark and Beach Boys Mike Love and Bruce Johnston. Also, Jan Berry himself and his parents appear in the audience at the end of the movie.