Altered Dominant
Bb7alt is an altered dominant chord on Bb. It contains every possible chromatic alteration (#9, b9, #5, b5), creating maximum tension before resolution. Levine describes altered dominants as the most colourful way to approach a tonic chord (The Jazz Piano Book).
33 voicings · altered
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Left Hand
Right Hand
Melody (Ab5) doubled an octave below (Ab4) with chord tones in between
Left hand alternates between bass note and chord
Beat 1 & 3 — Bb3
Beat 2 & 4 — D, E, Ab
Left hand alternates between bass note and chord
Beat 1 & 3 — F3
Beat 2 & 4 — D, E, Ab
The altered dominant contains all four altered tensions: b9, #9, b5 (#11), and #5 (b13). According to Levine, the altered scale (the seventh mode of melodic minor) provides all these tensions in one scale (The Jazz Theory Book). Upper structure triads are the most effective voicing technique for altered dominants — placing a triad over the tritone produces rich, specific colours.
The altered scale (seventh mode of melodic minor, a half step above the root) is the standard scale choice. Also known as the "super Locrian" scale (Levine, The Jazz Theory Book). All four altered tensions are diatonic to this scale.
Altered dominants resolve the same way as regular dominants — down a fifth to the tonic. The altered tensions (b9, #9, b13) all resolve by step into the notes of the target chord (Levine, The Jazz Theory Book).
ii-V-I with altered V
m7 — Bb7alt — maj7 for maximum tension and release
Tritone substitution
Bb7alt can substitute for the dominant a tritone away
Bb7alt is a dominant chord with all available tensions altered (b9, #9, #11/b5, b13/#5). It creates the most intense version of dominant tension in jazz harmony (Levine, The Jazz Theory Book).
Use Bb7alt when you want maximum harmonic tension before a resolution. It is most effective in minor key ii-V-i progressions and at climactic moments in a song. Levine recommends it whenever a dominant chord resolves to a minor chord (The Jazz Piano Book).
The altered scale is the seventh mode of melodic minor. Play the melodic minor scale starting a half step above the root of the dominant chord.
— Levine, The Jazz Theory Book, pp. 70-74
Upper structure triads over altered dominants produce six distinct colours, each suitable for different musical contexts.
— Levine, The Jazz Piano Book, pp. 115-130