G#7sus4

Construction

Built from these intervals: 1-4-5-b7.

The 4 replaces the 3 -- this is a suspension, meaning the third is not absent but actively replaced by a neighboring tone. That replacement removes the tritone that defines standard dominant function (the tritone lives between 3 and b7; with 4 instead of 3, the interval from 4 to b7 is a perfect fourth, not a tritone). The b7 still adds dominant weight, but without the tritone there is no urgent pull toward resolution.

Harmonic Function

In Roman numeral analysis (uppercase = major, lowercase = minor):

• V7sus4 in any key -- dominant that suspends before resolving. Often precedes V7 (7sus4 to 7 to I), creating staged tension: first the suspension resolves, then the dominant resolves.
• I7sus4 in funk and R&B -- groove chord that sustains indefinitely, no urgency to move. The b7 gives it harmonic weight; the missing 3 keeps it open.
• Mixolydian vamp -- Mixolydian is a mode (a scale built on the fifth degree of the major scale) with the formula 1-2-3-4-5-6-b7. The 4 and b7 in 7sus4 outline this mode, making the chord a natural home for improvisation. A vamp is a repeating figure, and 7sus4 excels in that role.

Character

Open and grounded. The b7 adds weight while the missing 3 creates ambiguity -- the chord neither pushes toward resolution nor fully settles. This is the sound of Herbie Hancock's modal jazz and 1970s soul, grooves that breathe without going anywhere. Compare to sus4: both replace the 3 with 4, but 7sus4 adds the b7, which gives the chord dominant color and harmonic weight that plain sus4 lacks. That b7 is what lets 7sus4 vamp indefinitely in funk where sus4 tends toward classical resolution.

Related Sounds

These chords are closely related -- each modifies one interval:

• 7 (1-3-5-b7) -- resolve the suspension by dropping the 4 back to 3, restoring the tritone and full dominant drive
• sus4 (1-4-5) -- nearest neighbor; same suspension without the b7, lighter and more inclined to resolve
• 11 (1-3-5-b7-9-11) -- has both 3 and 11 plus a 9; different structure despite similar open sound when the 3 is omitted
• min7 (1-b3-5-b7) -- another chord with b7 and no tritone, but b3 gives it minor quality where 7sus4 stays ambiguous
• Implies Mixolydian (1-2-3-4-5-6-b7) -- the 4 and b7 together outline this mode, making it the natural scale for improvising over 7sus4

Voice Leading

Voice leading tracks how individual notes move from one chord to the next. The 7sus4 creates two layers of potential resolution -- the suspension (4 to 3) and the dominant function (b7 to 3 of I) -- and how you sequence them shapes the musical effect.

• V7sus4 to V7: The 4 drops a half step to the 3. This single motion resolves the suspension while activating the tritone -- staged tension in one move.
• V7sus4 to I: The 4 holds as the root of I. The b7 drops a half step to the 3 of I. The suspension skips its own resolution and moves directly to the tonic.
• V7sus4 to V7 to I: Full sequence. The 4 drops to the 3 (suspension resolves), then the 3 rises a half step to the root of I and the b7 drops a half step to the 3 of I (tritone resolves). Two resolutions in series.

These movements apply in any key -- the intervals are the same regardless of root.

Practice Seeds

Delayed resolution. Hold V7sus4 for several bars, then resolve to V7, then to I. Feel how the suspension extends the dominant function -- tension builds in stages rather than all at once.

7sus4 vs. sus4. Play a sus4 and a 7sus4 from the same root. The b7 is the only difference. Hear how it transforms a chord that wants to resolve into one that can sit indefinitely -- this is the interval that separates them.

Funk vamp. Loop a single I7sus4 with rhythmic variations. Experience the chord as a groove foundation rather than a transition point -- this is its natural role in funk and R&B, where a single chord can carry an entire song.

Modal improvisation. Play a 7sus4 and improvise using the Mixolydian scale over it. The 4 and b7 in the chord match the mode's signature tones -- this builds awareness of how chord tones and scale tones align.