Welcome to... "Micro-Lesson 240"
The riff is organized around two popular chords from the "Dorian" harmony. These include the "Minor 7th" Tonic chord and the "Dominant 7th" IV-chord. These make up the most common ideas used in the world of Dorian Mode Riffs.
Our riff is in the, "C Dorian Mode," and in measure one, the "C m7" chord enters upon the root tone on beat one of the measure and the two principle harmony tones of it's harmony, (the minor 3rd and minor 7th) are applied upon beat two.
In measure two, the "F7" chord appears and uses only the root, 3rd and b7th tones to color the arrival into the measure. The remainder of this bar is made up of a, "C Minor Pentatonic," scale lick.
Measure three is a carbon copy of measure one. However, measure four applies a new twist to the Minor Pentatonic run from measure two and wraps up the line so that this phrase can repeat.
Take your time learning the parts as they need to be well memorized in order to be performed up to tempo. Enjoy!
Micro Lesson 240: "C Dorian" Soul /RandB Riff