9b5 chords

The 9th flat 5th chord is an alternate ninth chord. This chord is a dominant ninth with a flattened fifth. By comparing C9 with C9b5 we can see that the notes change from C, E, G, Bb, D to C, E, Gb, Bb, D. The chord is sometimes written 9(b5), in which the parentheses make it clearer, or as C9-5 with the minus replacing the flat symbol. It can also be written as 9#11 (the sharp 11th is the raised 4th on the next octave).

Due to the problematic finger positions this chord isn't that popular on the guitar. The chord is most often played with the root on the fifth string as in the movable shape presented below (notice that the index finger should be used as a barre pressing down the 4th and 1st strings).

9b5 (9#11)

C9b5

  • C9b5 chord diagram

C#9b5

  • C#9b5 chord diagram

D9b5

  • D9b5 chord diagram

Eb9b5

  • D#9b5 chord diagram

E9b5

  • E9b5 chord diagram

F9b5

  • F9b5 chord diagram

F#9b5

  • F#9b5 chord diagram

G9b5

  • G9b5 chord diagram

G#9b5

  • G#9b5 chord diagram

A9b5

  • A9b5 chord diagram

Bb9b5

  • A#9b5 chord diagram

B9b5

  • B7b9 chord diagram

Comments

A more convenient option for C9b5 might be as X34330 without the need for laying the index finger over several strings. A9b5 can also be played in open position with the 3rd omitted as X0100X. An option for G9b5 not so far up the neck is 32322X.

Alternate fingering

As told, this chord can be tricky on the guitar. There is however a possibility to finger 9#11 using two fingers! This will omit the 3rd (not unusual in dominant chords) and one example is D9#11 as x5655X with the index finger barring the 5th fret:

D9b5 chord diagram X5655X

Chord structure

The ninth flat fifth is built with the formula 1-3-b5-b7-9. This includes the root (1), the third (3), the flattened fifth (b5), the minor seventh (b7) and the ninth (9).

Notes in chord

C9b5  C - E - Gb - Bb - D
C#9b5  C# - F - G - B - D#
D9b5 D - F# - Ab - C - E
D#9b5  D# - G - A - C# - F
E9b5  E - G# - Bb - D - F#
F9b5  F - A - B - D# - G
F#9b5  F# - A# - C - E - G#ยค
G9b5  G - B - Db - F - A
G#9b5  G# - C - D - F#- A#
A9b5  A - C# - Eb - G - B
A#9b5  A# - D - E - G# - C
B9b5  B - D# - F - A - C#
The intervals are 1 - 3 - b5 - b7 - 9

Chord progressions

Progressions including this chord type:

Gmaj7 - C9b5

Amaj7 (5X665X) - D9b5 (X5655X)

Chord comparisons

The ninth flat five chord has similarities with the dominant ninth and the ninth sharp five:

Notes in chord

C9 C - E - G - Bb - D
C9b5 C - E - Gb - Bb - D
C9#5 C - E - G# - Bb - D
Theoretical order of notes


See other alternate chords.

Back to chord types

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