B7(#11,b13)/b9 Dominant 7th

The B7(#11,b13)/b9 chord is built from the notes B – D# – F# – A – C – E# – G.

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Also known as

B7(#11b13)/b9B7(b9b13)(#4)B7-alt7B7alt(b9)B7altb9

Chord tones, one by one

BRoot

Root

The fundamental note the chord is built on — B.

D#Third

Major third

Four semitones — makes the chord major (brighter, happier).

F#Fifth

Perfect fifth

Seven semitones — the most stable interval, reinforces the root.

ASeventh

Minor seventh (♭7)

Ten semitones — the dominant/minor seventh. Adds bluesy tension (7, m7).

CExtension

Flat ninth (♭9)

A ♭9 — sharp, dissonant tension typical of altered dominant chords.

E#Extension

Sharp eleventh (♯11)

A ♯11 — the bright, floating Lydian color.

GExtension

Flat thirteenth (♭13)

A ♭13 — dark altered tension over a dominant chord.

🎹 Modal analysis

This chord is so rich it doesn't fit a single scale: it's a polychord (an “upper structure”) that stacks tensions from several scales at once. It doesn't work like a dominant that “wants” to resolve — it's pure color: picture one triad floating over an unrelated bass, the kind of sound used in reharmonization and modal passages. To make sense of it, follow the note-by-note breakdown above.

🎸 Genres

Modern jazz · Fusion · Film & TV scoring · Impressionism

7(#11,b13)/b9 in every key

More B chords