F♯ augmented major 7th chord on bass (F♯augMaj7)

Why it sounds like that

F♯ augmented major 7th is built as 1–3–♯5–7, with major thirds between F♯ and A♯, and A♯ and C♯♯. The double-sharped fifth C♯♯ (enharmonically D) gives the chord its augmented colour, while the major seventh E♯ adds brightness. Compare F♯ major 7th, which has a perfect fifth C♯.

What goes wrong with F♯ augmented major 7th?

• Letting the pinky collapse onto the 1st string, causing a buzz.
• Allowing the index finger to touch the 3rd string, deadening the A♯.

When to use it

F♯ augmented major 7th works as a passing chord between F♯ major and B♭ major, or as a substitute for F♯ major 7th in jazz. Its bright, tense sound suits modern jazz and fusion.

Changing to and from F♯ augmented major 7th

• Sliding the shape down two frets to the 6th fret gives E augmented major 7th.
• Sliding the shape down one fret to the 7th fret gives F augmented major 7th.

Which voicing to use

The C♯♯ inversion places the augmented fifth in the bass, creating a restless, upward-pulling sound. The E♯ inversion puts the major seventh in the bass, which darkens the chord and works well for descending bass lines.