What is the Bb Altered Scale?
The altered scale (also called Super Locrian) is the seventh mode of the melodic minor scale, and it lives up to its name — every possible tension is altered (♭9, #9, ♭5/#11, #5/♭13). It's the ultimate dominant tension scale in jazz, used over V7 chords when you want maximum harmonic tension before resolving. Here's how the Bb Altered Scale lays out on the fretboard. This scale is enharmonically equivalent to A# Altered.
Notes and Positions
All altered tensions over V7; 7th mode of melodic minor. On guitar, you can treat this as both a lead vocabulary and a way to see chord tones inside common shapes. Start with one box, then connect it to the nearest root on the next string set. In the key of Bb, the notes are: Bb, Cb, C#, D, E, Gb, Ab.
How to Use It
You'll often hear it in Jazz, Fusion, and Altered dominant chords. A good way to internalize the sound is to sing the root, then sing a few scale degrees before you play them.
Practice in small fragments (3-4 notes) and connect them across adjacent positions. Use the interactive fretboard above to spot repeats of the same note on different strings and frets.