Bb-alt11 Minor 7th
The Bb-alt11 chord is built from the notes Bb – Db – F – Ab – E – G – Eb.
Piano sound loads on first tap.
Chord tones, one by one
Root
The fundamental note the chord is built on — Bb.
Minor third
Three semitones — makes the chord minor (darker, sadder).
Perfect fifth
Seven semitones — the most stable interval, reinforces the root.
Minor seventh (♭7)
Ten semitones — the dominant/minor seventh. Adds bluesy tension (7, m7).
Sharp eleventh (♯11)
A ♯11 — the bright, floating Lydian color.
Thirteenth (13)
A 13th — full, rich top extension.
Eleventh (11)
An 11th — a suspended, airy color on top of the 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