B♭ Super Locrian (Altered Scale)

Notes in the B♭ Super Locrian (Altered Scale)

Degree Name Note Frequency (A=440)
1 Tonic B♭ 466.164 Hz
♭2 Altered 2nd B 493.883 Hz
♭3 Minor Mediant D♭ 277.183 Hz
♭4 Altered 4th D 293.665 Hz
♭5 Tritone E 329.628 Hz
♭6 Altered 6th G♭ 369.994 Hz
♭7 Subtonic A♭ 415.305 Hz

Interval Pattern

Formula: H-W-H-W-W-W-W
Step Interval Semitones From Note To Note
1 Half Step (H) 1 B♭ B
2 Whole Step (W) 2 B D♭
3 Half Step (H) 1 D♭ D
4 Whole Step (W) 2 D E
5 Whole Step (W) 2 E G♭
6 Whole Step (W) 2 G♭ A♭
7 Whole Step (W) 2 A♭ B♭

Chords Built on Scale Degrees

Degree Note Chord Quality
1 B♭ B♭ diminished diminished
♭2 B B minor minor
♭3 D♭ D♭ minor minor
♭4 D D augmented augmented
♭5 E E major
♭6 G♭ G♭ major
♭7 A♭ A♭ diminished diminished

Key Signature

2 — The B♭ key signature uses B♭, E♭.

B♭ Super Locrian (Altered Scale) in Practice

The B♭ Super Locrian (Altered Scale) uses the key signature of 2 flats (B♭, E♭). Bb major has two flats (Bb, Eb) and is extremely common in jazz and wind ensemble music. It is the home key for Bb instruments such as the trumpet and tenor saxophone. On guitar, B♭ positions offer comfortable transposing instrument keys for this scale.

The Super Locrian (or Altered scale) is mode VII of melodic minor. It contains every possible alteration of the dominant scale and is the definitive jazz scale for altered dominant chord resolution. When played starting on B♭, the 7 notes are B♭, B, D♭, D, E, G♭, A♭. In this key the signature has 2 flats (B♭, E♭). Bb is the concert-pitch key when Bb instruments (trumpet, clarinet, tenor sax) play in their native C, making it the most common jazz and band key. Jazz standards in Bb are ubiquitous — tunes like "Autumn Leaves" and "All Blues" sit naturally for horn sections, and the key is a default for jam sessions.

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

Note Equal Temp. Pythagorean Just Intonation
B♭ 466.164 Hz 463.538 Hz 470.926 Hz
B 493.883 Hz 495.000 Hz 490.548 Hz
D♭ 277.183 Hz 278.437 Hz 279.067 Hz
D 293.665 Hz 293.332 Hz 294.329 Hz
E 329.628 Hz 330.001 Hz 327.032 Hz
G♭ 369.994 Hz 371.251 Hz 367.911 Hz
A♭ 415.305 Hz 417.657 Hz 418.601 Hz

Related Scales

Transposing Instruments: B♭ Super Locrian (Altered Scale)

B♭ is a natural key for B♭ instruments (trumpet, clarinet, tenor sax), which sound a major second lower than written. B♭ instruments reading in C produce B♭ concert pitch. E♭ instruments (alto sax, baritone sax) reading in B♭ sound a major sixth lower.