Young Billy Young is a 1969 Western starring Robert Mitchum (and that's reason enough to watch it right there), Angie Dickinson, Robert Walker, Jr. (who has a ST:TOS connection), David Carradine (Kung Fu, Ingmar Bergman's only English Language film The Serpent's Egg, Kill Bill), Paul Fix (who has a ST:TOS connection) and Parley Baer (who has a ST:Voyager connection). Mitchum sings the title track.
Mitchum is looking for his son's killer. This is a traditional Western, nicely done. Carradine looks so young in this.
Reviews are hard to find. TCM has some information.