These four-note combinations (tetrachords) consist of triads (major, minor, diminished, and augmented) with major 2nd’s (or 9th’s) added above the root.
Tetrachords are a convenient method for creating unassailably harmonically-correct lines.
I find that improvising with these patterns (rather than intricate arpeggios, chord-scales, and modes, etc.) frees up brain processing power to think more about rhythm, phrasing, and line direction.
Try improvising lines through chord changes using these patterns.
Emphasize half-step resolutions between changing harmonies.
Anchor the patterns in your memory by focusing on the triad forms embedded in these diagrams.
I have written the patterns on the root “C,” but they are easily transposable by shifting the shapes to new root locations.
Major Tetrachord:
Minor Tetrachord:
Diminished Tetrachord:
Augmented Tetrachord: