"If You Don't Want To Get In Trouble" comes from the Spiritual Section of the book and is perfect for the Gospel-swing style that I had in mind for the last movement.
To begin the movement, the chorus is heard in the tuba while the left hand of the piano plays a bass line. This is followed by the verse in the tuba with piano chordal punctuation. At measure 17, the chorus is heard again, this time with a little flare inserted in the right hand of the piano. At measure 25, the piano plays a harmonized version of the chorus. This sections ends with chromaticism in both the tuba and piano that leads the listener into a louder, more intense section at measure 34. The material of this section is taken from motifs of the tune. A modulation up a half step at 42 adds to the excitement.
At 51, the chorus of the tune returns with tuba solo and piano accompaniment. This leads to a long tuba cadenza whose material is freely derived from motifs of the tune. After the cadenza settles down on a low tuba note, the piano returns with the harmonized version of the chorus and the tuba plays the ascending flares. The two measure chromatic section heard earlier returns before the tempo slows down to an "Amen" type cadence.
Below is a video of the score that uses sampled sounds. Your comments are always appreciated.