C Altered Scale (Super Locrian Scale)

C – Db – Eb – E – Gb – Ab – Bb – C
Formula:H-W-H-W-W-W-W
Intervals:P1-m2-m3-M3-A4-m6-m7-P8
Scale Degrees:1-♭9(♭2)-#9(♭3)-3-#11(♭5)-♭13(♭6)-♭7-8

Introduction

The C Altered Scale is the 7th mode of the Db Melodic Minor scale and the go-to choice for jazz improvisation over C7alt chords. Its notes are C - Db - Eb - E - Gb - Ab - Bb - C, containing every possible alteration of a dominant 7th chord: the b9, #9, b5/#11, and b13. This dense cluster of tensions makes it the most dissonant dominant scale available, creating powerful forward motion that resolves naturally to Fmaj7 or Fm.

C Altered Scale (Super Locrian Scale) Notes

DegreeNameNoteInterval
1TonicC4P1
♭9(♭2)SupertonicC#4m2
#9(♭3)MediantD#4m3
3SubdominantE4M3
#11(♭5)DominantF#4A4
♭13(♭6)SubmediantG#4m6
♭7Leading ToneA#4m7
8OctaveC5P8

Key Signature

The key of C Altered Scale has No sharps or flats.

Chords in the Key of C Altered Scale

These are the diatonic triads built on each degree of the C Altered Scale (Super Locrian Scale):

DegreeNumeralChordQuality
1IC MajorMajor
2iiD MinorMinor
3iiiE MinorMinor
4IVF MajorMajor
5VG MajorMajor
6viA MinorMinor
7vii°B DiminishedDiminished

C Altered Scale (Super Locrian Scale) — Frequently Asked Questions

What notes are in the C Altered Scale?

The C Altered Scale contains seven notes: C Db Eb E Gb Ab Bb (plus the octave). It is the 7th mode of the Db Melodic Minor scale — playing Db Melodic Minor starting on C produces the C Altered Scale. It contains all four possible alterations of a dominant chord: b9 (Db), #9 (Eb), #11/b5 (Gb), and b13 (Ab).

What chord is the C Altered Scale used over?

The C Altered Scale is used almost exclusively over C7alt — a dominant 7th chord with alterations. It creates maximum harmonic tension before resolving to the tonic chord a fifth below. In a ii–V–I progression, the altered scale goes on the V chord (C7alt) to create powerful tension that resolves into the I chord.

What is the fastest way to find the C Altered Scale?

The shortcut: play Db Melodic Minor starting on C. Every note of Db Melodic Minor, starting from C, gives you the C Altered Scale. Once you know your melodic minor scales, finding any altered scale is immediate — just start the melodic minor from its 7th degree.

Why is the altered scale called "Super Locrian"?

The C Altered Scale is identical to the Locrian mode except it also lowers the 2nd degree (making it b2 / b9). This extra lowering gives it even more tension than Locrian, earning it the name "Super Locrian." The interval formula is H–W–H–W–W–W–W.

How does the C Altered Scale differ from the C Dominant 7th scale (Mixolydian)?

C Mixolydian (the standard dominant scale) uses the natural 2nd, 3rd, 5th, and 6th. The C Altered Scale alters all of these — the 2nd becomes b9 (Db), the 3rd becomes #9 (Eb), the 5th becomes b5 (Gb), and the 6th becomes b13 (Ab). This maximises tension and is why jazz musicians call it the "altered" dominant.

What music uses the C Altered Scale?

The C Altered Scale is used in jazz improvisation, especially in bebop, post-bop, and fusion. It appears over altered dominant chords in ii–V–I progressions, turnarounds, and secondary dominants. Famous jazz pianists including Bill Evans, Herbie Hancock, and Brad Mehldau use altered scales extensively.

Practice Tips

  • Remember the shortcut: C Altered Scale = Db Melodic Minor starting on C. Learn Db Melodic Minor first if you haven't already.
  • Practice the scale slowly, listening for the tension created by the b9 (Db), #9 (Eb), b5 (Gb), and b13 (Ab).
  • Play the C Altered Scale over a C7alt chord and resolve it to the tonic chord a fifth below — feel the tension-release that defines altered dominant harmony.
  • Use 3-4 note fragments rather than running the full scale — jazz phrasing uses small motifs, not scale runs.
  • Target the major 3rd and b7 of the C7alt chord as anchor tones; use the altered tensions (b9, #9, b13) as colour around them.
  • Listen to jazz recordings and identify when altered scales are used — the tense, "outside" sound before resolution is characteristic.