Gbm7b5 Piano Chord

Piano Diagram of Gbm7b5 in Root Position

The Gbm7b5 chord, also known as a half-diminished chord, is a minor dominant seventh chord with a flat 5th built on the Gb major scale. This chord consists of the root note Gb, the minor third Bbb (A), the diminished fifth Dbb (C), and the minor seventh Fb (E).

 

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Structure of Gbm7b5

 

Gbm7b5 Chord Inversions

 

The Gbm7b5 chord has a total of 3 inversions:

 Piano Keyboard Diagrams

 

Gbm7b5 Chord Equivalencies

When you invert a half-diminished chord to its first inversion, it becomes equivalent to a minor 6th chord built on its minor 3rd.

Let’s take the Gbm7b5 chord which consists of the notes Gb, Bbb, Dbb, Fb: its first inversion is Bbb (A), Dbb (C), Fb (E), Gb (F#), which is also an A min6 chord.

1st Inversion of Gbm7b5 = A minor 6th

Understanding the equivalencies of chords can be beneficial when playing or composing music. It can also help in analyzing and understanding the harmonic structure of a piece of music.

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Music Theory and Harmony of Gbm7b5

 

Gbm7b5 is considered a half-diminished chord, which means it has a diminished fifth and a minor seventh interval. This chord can be used as a substitute for other chords, such as a dominant seventh chord or a minor chord.

In jazz and other styles of music, Gbm7b5 is often used as a passing chord or as part of a ii-V-I progression. It can add tension and interest to a musical passage, and can also be used as a starting point for improvisation.

Before examining the most common use of this chord, let’s learn how to build it.

 

Building the Gbm7b5 Chord: Different Approaches

Starting from the Gb Major Scale:

To form a minor 7b5 chord, you would typically include the root note, minor third, diminished fifth, and minor seventh from a minor scale.

However, when teaching this concept, it can be more effective to demonstrate its construction using a major scale. This is because a major scale better illustrates the relationship between intervals and their respective qualities.

So let’s take the Gb major scale:

 

 

 

To create a Gbm7b5 chord, apply the formula R, m3, d5, m7 in the following manner:

1. Begin with the Root note, Gb.
2. Select the third interval, which is Bb. Then, subtract a half step to obtain the minor 3rd, Bbb.
3. Select the 5th interval, which is Db then lower it by half step to get the diminished 5th, Dbb.
4. Pick the 7th interval F, then lower it by a half step to get the minor 7th, Fb.

By following this simple formula, you can create a minor 7b5 chord from any major scale.

 

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by Combining Intervals:

One method to create a Gbm7b5 chord is by combining specific intervals – a minor 3rd, another minor 3rd, and a major 3rd.

m3 + m3 + 3 = m7b5 Chords

For example, to build a Gbm7b5 chord:

• we start with the root note Gb.
• We then add a minor 3rd interval, which is three half-steps up from the root, to get A (Bbb).
• Next, we add another minor 3rd interval, which is three half-steps up from A, to get C (Dbb).
• Finally, we add a major 3rd interval, which is four half-steps up from C, to get E (Fb).

Together, these intervals form the Gbm7b5 chord.

 

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How to Use Gbm7b5 in a Chord Progression

 

The Gbm7b5 chord is frequently used in ii-V-I progressions, where it functions as the ii chord. However, due to its versatile nature, it can also be used in various other musical contexts, such as:

• on natural minor and Major keys
• as a substitute for dominant 7th chords
• as a substitute for minor chords

Most common uses of Gbm7b5

The Gbm7b5 chord appears on the second scale degree (II) in the Fb natural minor scale and on the seventh scale degree (VII) in the Abb major scale; both are theoretical keys so we will refer to their enharmonic equivalent keys E minor and G major.

 

• Supertonic chord in E minor

 

• Leading tone chord in G Major

 

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Gbm7b5 as a Substitute for Dominant 7th Chords

Minor 7th flat 5th chords can replace dominant 7th chords when they share some of the same notes. A general rule of thumb when it comes to chord substitutions is that if the substitute chord contains at least the 3rd and 7th notes of the original chord, it’s often a viable option for substitution.

Ab7 ⇔ Gbm7b5

D7 ⇔ Gbm7b5

In this case, the Gbm7b5 chord (Gb, Bbb, Dbb, Fb) can serve as a substitute for Ab7 (Ab, C, Eb, Gb) and D7 (D, F#, A, C) due to their shared notes. Specifically, Gbm7b5 shares the 7th and 3rd notes of Ab7 (which are Gb and C, respectively), as well as the 3rd and 7th notes of D7 (which are F# and C).

Rootless dominant 9th Chord Substitution

It’s worth noting that the substitution of D7 with Gbm7b5 can also be viewed as a rootless dominant 9th chord substitution. This is because Gbm7b5 contains the same essential notes as the D9 chord except the root note.

D9 = D (F#, A, C, E)

Gbm7b5 = Gb, Bbb, Dbb, Fb

 

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Gbm7b5 as a Substitute for minor Chords

Check F#m7b5 as a Substitute for minor Chords

 

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Gbm7b5 as Supertonic Chord in Fb minor

Check F#m7b5 in E minor

 

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Gbm7b5 as Leading Tone Chord in Abb Major

Check F#m7b5 in G Major

 

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Gbm7b5 as Substitute for Ab7

Gbm7b5 shares the 7th and 3rd notes of Ab7 so it’s possible to use a Gbm7b5 in place of an Ab7 on the V degree. This is a common substitution used in jazz music and can add some interesting harmonic color to a progression.

 

ii V I

 

I IV ii V iii vi ii V

You can play the Gbm7b5 chord by itself, or use it in combination with an Ab7 chord, either before or after the Gbm7b5. This will allow you to explore the different tonal colors and tensions that each progression creates, and help you develop a stronger sense of how these chords can be used effectively in your musical compositions or improvisations.

 

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Gbm7b5 as Substitute for D7

Check F#m7b5 as Substitute for D7

 

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Alternative Gbm7b5 Nomenclature

• Gbø
• Gb∅
• Solb ø
• Gbm7^b5
• Gbm7°5
• Gbm7b5
• Gbm7/b5
• Gbm7(-5)
• Gbm7(b5)
• Gb 1/2dim
• Gb 1/2dim7
• Gbm7 Flat 5
• Gb minor 7th b5
• Gb half-diminished
• Gb minor seventh flat fifth

 

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