Guest, A H White, this is a music discussion forum. We're interested in lots of performers and their music.

A Google search on Richard Gillis comes up with some information.

This talks about the movie of reference specifically. From the site:

Peckinpah decided to utilise the songs of Richard Gillis for his movie. You may not have heard of Richard Gillis. This is because he was a bar singer the director just happened to come across, and he hired him there and then on a whim. He was even going to get him to write the movie's score, but wiser heads prevailed and Goldsmith got the gig.

Saddled (pun intended) with having to work with Gillis's songs as a centrepiece, Goldsmith did not get much of a chance to make an impression with his score. (Indeed, of the 37 minutes of music on this album, which is a complete musical representation of the picture, only about 20 minutes make up original score - then there's six minutes worth of Goldsmith songs and eleven minutes of Gillis compositions.) Probably the most impressive contribution by Goldsmith is his song, "Tomorrow is the Song I Sing", a laid-back western ballad sung, reasonably appealingly, by Gillis. Not one to stick in the memory, but pleasant enough.

His score is exceptionally low-key, performed for the most part by a tiny ensemble at any one time. There's a lovely piece for flute, guitar and harmonica - "The Rattlesnakes" - "Three Hours Early" is a real barnstormer, over far too quickly - and when the melody from Goldsmith's song is worked into the score, it works a treat. The music struggles to leave much of an impression, however - it is an acquired taste for sure, much more along the lines of the subtle, bucolic sections of Wild Rovers than the wild, wild west Americana of Rio Conchos.

http://www.imdb.com/name/nm0319311/ is the first place anyone should look for movie information in this day and age. (And on a personal note, I haven't seen Cable Hogue, but many years ago I saw the dystopian drama A Boy And His Dog and didn't notice the music, so I'll have to go back and give it a listen.)

SRS