Construction
Step pattern (W = whole step, H = half step; m3 = minor third, 3 half steps): W-m3-W-W-H-W.
Formula (intervals from the root): 1-2-4-5-6-b7.
This six-note scale is Mixolydian (the 5th mode of major, a dominant-sounding scale: 1-2-3-4-5-6-b7) with the 3rd removed. The formula is close to major pentatonic (1-2-3-5-6) -- replacing the 3 with 4 and adding b7 shifts the sound from consonant to groove-oriented. The "sus" refers to the perfect 4th replacing the 3rd -- the scale cannot declare major or minor, leaving it permanently open and unresolved.
Origin and Relationships
- Base scale: Mixolydian (1-2-3-4-5-6-b7). Removing the 3 produces the Dominant Sus formula. The b7 retains dominant character while the absent 3rd creates suspended quality.
- Family: Synthetic/modified. A six-note scale, not pentatonic -- it has one note more than a pentatonic and one fewer than a standard mode.
- Quartal affinity: The scale naturally produces stacked fourths (1-4-b7), which is why it pairs so well with quartal voicings (chords built by stacking intervals of a fourth rather than thirds) used in jazz and fusion.
Harmonic Context
- 7sus4 (dominant sus4): The scale's home chord. 1-4-5-b7 spells a dominant 7th with the 4th replacing the 3rd.
- 9sus4 (a sus4 chord with an added 9th), 13sus4 (a sus4 chord with an added 13th): Extended suspended dominant voicings. The 2 serves as the 9th, the 6 as the 13th.
- Quartal harmony: Chords built in stacked fourths (1-4-b7, 2-5-1, etc.) emerge naturally from the scale's intervals.
- Modal vamp: Over a static 7sus4, the scale sustains ambiguity indefinitely -- it grooves without resolving.
Characteristic Tones
The intervals that give this scale its distinctive sound:
- 4 (perfect fourth): Replaces the 3rd entirely -- the scale declares neither major nor minor, leaving the harmony permanently suspended. This is what makes the scale "sus": the 4th occupies the space where a major or minor 3rd would declare the chord's quality.
- b7 (minor seventh): Provides dominant pull without a leading tone. Combined with the absent 3rd, it creates a sound that wants to move but has no clear destination.
Melodic Applications
Target the 4 and b7 as phrase anchors -- these are the chord tones of 7sus4, and landing on them reinforces the suspended character. The 2 and 6 act as melodic connectors between the fourths, adding motion without introducing major/minor bias. Over a funk or fusion vamp, the quartal intervals (1 to 4, 4 to b7) are the melodic backbone. Compare to Mixolydian: adding a 3rd to any phrase immediately breaks the suspension, so the discipline is in what you leave out.
Practice Seeds
Quartal stacking. Play 1-4-b7 as a melodic shape, then shift it through the scale (2-5-1, 4-b7-4, etc.). Hear the fourths that are built into the scale's structure.
7sus4 vamp. Improvise over a static 7sus4 chord, landing on 4 and b7 as resting points. Experience how the scale sustains groove without resolving -- it can sit in one place indefinitely.
Mixolydian comparison. Play Mixolydian and Dominant Sus from the same root, noticing where the 3rd would fall. Hear what removing one note does -- major definition vanishes, replaced by open space.
Funk pocket. Build short, rhythmic phrases emphasizing the 1-4-b7 quartal shape with syncopated timing. Develop the percussive, groove-oriented phrasing that suits funk and fusion contexts.