The augmented scale alternates minor 3rds and half steps: C-D#-E-G-Ab-B. Six notes, only 4 unique transpositions. It’s the lesser-known sibling of the whole-tone and diminished scales.
The Scale on the Fretboard
Structure
Formula: 1 - #2 - 3 - 5 - b6 - 7. Notice it contains two augmented triads a half step apart: C-E-G# and Eb-G-B. This dual augmented structure is what gives the scale its shimmering, otherworldly sound.
Usage
Play over augmented triads and maj7#5 chords. John Coltrane used augmented structures extensively in his "sheets of sound" period. The scale works over Coltrane changes (major 3rd cycles) because augmented triads divide the octave into major 3rds.
The 4-Fret Symmetry
Since there are only 4 transpositions, augmented scale shapes repeat every 4 frets on the P4 fretboard. Any pattern you learn can be shifted up 4 frets and it produces a valid transposition. Combined with the 3-fret diminished and 2-fret whole-tone repetitions, symmetric scales turn the fretboard into a kaleidoscope.