"Transmograpfication'" (PDF) from the James Brown album, Slaughter's Big Rip-Off.

Coming off of the success from the Black Caesar soundtrack, James Brown and Fred Wesley team up again to provide the music for their second feature film, 1973's Slaughter's Big Rip-Off.  Having learned a few lessons from their initial collaboration, Wesley had earned the trust of his boss to oversee the direction of the project.  As a result, Fred Wesley's artistic vision brings a different sound and production value that normally would not be associated with the James Brown band, including this dark and adventurous trombone solo that appears early on the soundtrack.

What sets "Transmogripfication" apart from other J.B. vamps is the gradual build up of tension through the exploration of sound, rather than just tightening up the groove.  As the tune progresses, more instruments come in to play adding extensions to the harmony and providing passing melodies that add moments of dissonance.  Likewise, Fred branches beyond the usual minor pentatonic scales by including the use of the melodic minor, blues, and dorian scales, to add a level of depth to his improvised melodies.

Although the entire track is around two minutes in length, Wesley plays with a sense of patience and takes his time to develop longer phrases through the use of repetition, and he gradually builds the tension one scale degree at a time.  Scales have a natural tension built in, and Fred explores the sound of the unusual intervals.  And even as one phrase winds down, the next phrase will begin immediately, never giving the listener any time to get too comfortable.  Remember, this is not the "feel-good" movie of the year.

Here is a YouTube video of the trailer for Slaughter's Big Rip-Off, including Mr. Wesley's name in the credits (don't blink).

Recommended Reading: Hit Me, Fred: Recollections of a Sideman by Fred Wesley Jr.  Published by Duke University Press.