Dominant Seventh Flat Five Chords (7b5) | Guitar Diagrams and Voicings

Dominant Seventh Flat Five (7♭5) Chords – Guitar Voicings & Diagrams

This page explores the 7♭5 chord—a dominant seventh with a diminished fifth—commonly used in jazz for tritone substitutions and smooth voice leading.

It includes guitar diagrams, Drop-2 and Drop 3 voicings, and II–V–I examples to apply the chord in context.

What's a Dominant 7b5 Chord?

The dominant seventh flat five chord (7b5) is a dominant seventh chord with a fifth lowered by a semitone.

It is built with a root (1), a major third (3), a diminished fifth (b5) and a minor seventh (b7).

The dominant b5 chord is an extremely important sound in jazz music due to its dissonant and unresolved sound.

Symbols and Notation

Dominant 7 flat 5 chords can be written 7b5 or 7^(b5).

Usual Extensions

7b5 chords can be extended with : b9, 9,  #9, b13, 13.

Drop 2 Voicings

Here are the 4 dominant 7b5 drop 2 voicings related to the twelve guitar shapes below.

One thing to know is that there are only two different fingerings for any 7b5 chord on any string set. You only need to learn two different fingerings per string. 

Drop 3 Voicings

Drop 3 voicing is the process of taking the third highest note of a close voicing and dropping it an octave.

This way you obtain a new voicing (R b7 3 b5) that you can inverse in three different ways :

• 3 R b5 b7 
• b5 3 b7 R
• b7 b5 R 3

This four drop 3 voicings provide four 7b5 chord positions as shown in the diagrams below.

Difference With 7#11 Chords.

Because this topic is often confusing, it is important to make it clear.

By taking a dominant 7 chord, R, 3, 5, b7, and lowering the 5th by a 1/2 step we obtain the following formula : R, 3, b5 (#11), b7.

Because the flat fifth (b5) can be considered as a sharp eleventh (#11), 7b5 and 7#5 chords are often confused. 

Dominant seventh sharp eleventh chord symbols (7#11) arise often in big band charts and standard tunes. But in theory, these two chords are completely different.

Dominant 7b5 chords imply only 4 notes, unlike 7#11 chords are made up of 6 notes.

However, all the 7b5 diagrams shown below can serve as dominant 7#11, but the ninth and the perfect fifth will be omitted.

• 7b5 chords are built with : 1 (root), 3 (third), b5 (flat fifth), b7 (minor seventh).
• 7#11 chords imply all of these tones : 1 (root), 3 (third), 5 (fifth), b7 (minor seventh), 9 (ninth), #11 (sharp eleventh).

Substitutions

7b5 chords are often used in jazz standards, giving a distinct sound flavor.Try to substituting ordinary dominant 7th chords with 7b5 chords in your favorite songs.

The Tritone Substitution

A common chord substitution found in jazz is where the V of a II V I sequence is replaced by a dominant 7th chord whose root is a tritone below.

Here is a first example with Dm7 | G7 | Cmaj7.  Db7 can be in place of the G7, thus giving Dm7 | Db7 | Cmaj7.

This is a great sound because with this kind of substitution, the root of the V chord is chromatic. We get a bass line descending by half steps (D to Db to C).

This kind of downward trajectory produces a pull towards the tonic chord. It is often a nice and featured sound in jazz.

Now that is where the 7b5 chord comes into play. Indeed, you can play it instead of the Db7. In other words, you just have to lower the fifth by a semitone, giving Dm7 | Db7b5 | Cmaj7. This way the b5 of Db7b5 (G) is none other than the V of Cmaj7.

Another example using drop 3 chords, in the key of Bb with a chromatic descending bass line (C, B and Bb).