Alan Williams raises the issue of what kinds of differences can intimate knowledge between rhythm section players bring to a session. I know from my work with the rhythm section at  Stax Records that rhythm guitarist Steve Cropper and drummer Al Jackson developed a way of playing where they would delay the back beat creating deliberate asymmetry between the placement of the four beats in a bar. This stood in stark contrast to the approach of the Motown rhythm section and is certainly a key component of th so-called "Stax sound." I doubt that this would have been easily attained, let alone maintained, over dozens of recording sessions for several years if these two players were not working with each other on a daily basis.

Paul Theberge brought up a number of questions with regard to click tracks. We can go further and ask what effect does the tracking of a rhythm section without a vocalist have on the final recording? Bassist Duck Dunn was used to cutting at Stax with the vocalist recording at the same time. He told me that when he moved out to Los Angeles in the 1970s and started doing tracking sessions it forced him to change the very nature of his bass lines. At Stax he would develop lines that complimented the vocal part both in terms of note placement (making sure he played around the vocal line) and pitch content (he often tried to create contrapuntal lines that related to the vocal melody). In Los Angeles, he was reduced to marking chord changes and was much more limitedwith regard to what kinds of grooves he might play.