| Mystery solved- there is not much on the net about the musicians who played on the movie soundtrack but it looks like it was Wilbur Bascomb, who also played on Jeff Beck's 'Wired'. From an interview with him about the session:
"It was August 1978, at A&R Studios, which used to be on 48th Street in New York. On the date with me were Galt McDermott, [drummer] Bernard Purdie, and [guitarist] Charlie Brown"
Apparently, they have these same players for the current broadway production.
If you haven't heard this soundtrack it is some killer rhythm section work! | 
