Right you are, PoppaGator. The most interesting facet of the movie was the stability of the session personel. I suppose that their contemporaries were well aware of their identities and talents. Still, I dont remember seeing any of those musicians when I worked in NYC in the late 60's. It could be that every city had its own session stars. I know that I saw the same sidemen time and time again at my studio (Associated Studio on 7th Ave) and at RCA, Columbia and A&M. It didn't seem to matter whether the session was for a demo or a master. The producers always hired musicians that they knew and trusted. Charlie Macey (on guitar) Irving Spice( violin) Eric Weisberg (on bass, 5 string or pedal steel) were a few of the regulars. Eric was still doing session work even after he had that hit with "Dueling Banjos".
Here, in Philly, Gamble and Huff had their own stable of session pros, none of whom were ever named or honored. Ernie Ransom's name comes to mind. I think that Elmer Snowden did some sessions for them too. Elmer had a very successful jazz band in the 20's and he was the guitarist on the classic Louis Armstrong/ Bessie Smith recording of "St. Louis Blues". But, when he worked for Gamble and Huff, he worked in the same shadow as the Funk Brothers in Detroit.