Tritone Substitution Guide: Jazz Harmony Explained | BeatKey Chord Finder

Tritone Substitution

Replace any dominant 7th chord with one a tritone (6 semitones) away for chromatic bass movement, richer color, and jazz-flavored resolutions. Used in bebop, neo-soul, R&B, and film scoring.

6
Semitones Apart
Root distance (tritone interval)
6
Tritone Pairs
12 dominant chords, 6 interchangeable pairs
Shared
3rd and 7th
Why the substitute resolves the same way

What Is a Tritone Substitution?

A tritone substitution (also called a tritone sub or tri-sub) replaces a dominant 7th chord with another dominant 7th chord whose root sits exactly 6 semitones away. Because the tritone divides the octave perfectly in half, every dominant chord has exactly one tritone substitute.

The substitute chord works because both chords share the same two notes that create the characteristic tritone tension: the 3rd and 7th of the original chord become the 7th and 3rd of the substitute chord (swapped). The resolution to the tonic is preserved because both notes still want to resolve by half steps.

The Classic Example: G7 to Db7

G7 (original)
Notes: G - B - D - F
Tritone interval: B (3rd) and F (7th)
B wants to resolve up to C. F wants to resolve down to E.
Db7 (tritone sub)
Notes: Db - F - Ab - Cb (B)
Tritone interval: F (3rd) and B/Cb (7th)
Same two notes, swapped roles. Db bass resolves down a half step to C.
Result: Dm7 - Db7 - Cmaj7 replaces Dm7 - G7 - Cmaj7. The bass walks D - Db - C (three descending half steps) instead of D - G - C (a leap up then a 4th down). The resolution is just as strong but far smoother.

Why It Works: Shared Tritone Theory

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Swapped Roles

The 3rd of G7 (B) is the enharmonic 7th of Db7. The 7th of G7 (F) is the 3rd of Db7. Same notes, different function.

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Chromatic Bass

Instead of a 5th leap (G to C), the bass moves a half step down (Db to C). Chromatic bass lines feel inevitable and smooth.

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Same Resolution

Both B and F (in G7) and F and B (in Db7) resolve identically to C and E, the root and 3rd of Cmaj7. The tonic arrival is unchanged.

The tritone (augmented 4th / diminished 5th) is the only interval that maps two dominant chords to each other. A perfect 5th apart would give you a different key center. Only the tritone creates this symmetric swap of 3rd and 7th.

Tritone Substitutions in All 12 Keys

Every dominant 7th chord pairs with exactly one tritone substitute. The six pairs cover all 12 dominant chords.

Original Dom7NotesTritone SubSub NotesShared TritoneBass Movement
G7G B D FDb7Db F Ab Cb (B)B / FG to Db (half step above C)
D7D F# A CAb7Ab C Eb Gb (F#)F# / CD to Ab (half step above G)
A7A C# E GEb7Eb G Bb Db (C#)C# / GA to Eb (half step above D)
E7E G# B DBb7Bb D F Ab (G#)G# / DE to Bb (half step above A)
B7B D# F# AF7F A C Eb (D#)D# / AB to F (half step above E)
F#7F# A# C# EC7C E G Bb (A#)A# / EF# to C (half step above B)
C7C E G BbF#7F# A# C# EE / BbC to F# (half step above F)
F7F A C EbB7B D# F# AA / EbF to B (half step above Bb)
Bb7Bb D F AbE7E G# B DD / AbBb to E (half step above Eb)
Eb7Eb G Bb DbA7A C# E GG / DbEb to A (half step above Ab)
Ab7Ab C Eb GbD7D F# A CC / GbAb to D (half step above Db)
Db7Db F Ab Cb (B)G7G B D FF / BDb to G (half step above F#)

Cb and B are enharmonically the same note. The table uses the enharmonic spelling that is most common in context.

The Formula: How to Find Any Tritone Sub

  1. 1
    Identify the dominant 7th chord you want to substitute. It must be a dominant 7th (1, 3, 5, b7) to work correctly.
  2. 2
    Count 6 semitones up (or down) from the root. G is 6 semitones above C#/Db. A is 6 semitones above Eb. Six steps either direction lands on the same note.
  3. 3
    Build a dominant 7th on that root. Formula: 1, 3, 5, b7. That is your tritone substitute.
  4. 4
    Update the bass line to the new root. The bass now resolves by half step instead of a 5th. Adjust your inner voices for smooth voice leading.

Tritone Substitution in Real Progressions

See how tritone subs transform common jazz and soul progressions:

ii-V-I (Jazz Cadence) in C major

Original
Dm7 - G7 - Cmaj7
With Tritone Sub
Dm7 - Db7 - Cmaj7
Classic bebop substitution. Bass moves D - Db - C chromatically.
Bass: D - Db - C (descending half steps)

I-VI-II-V (Turnaround) in C major

Original
Cmaj7 - A7 - Dm7 - G7
With Tritone Sub
Cmaj7 - Eb7 - Dm7 - Db7
Both dominant chords substituted. Creates chromatic bass descent.
Bass: C - Eb - D - Db (chromatic walk)

IV-V-I (Gospel Resolution) in C major

Original
Fmaj7 - G7 - Cmaj7
With Tritone Sub
Fmaj7 - Db7 - Cmaj7
Db7 approaches Cmaj7 from half step above. Rich gospel color.
Bass: F - Db - C

Blues with Tritone Subs in C blues

Original
C7 - F7 - G7
With Tritone Sub
C7 - B7 - Db7
Bebop blues approach. IV and V both substituted for chromatic bass.
Bass: C - B - Db - C (surrounding resolution)

Minor ii-V-i in C minor

Original
Dm7b5 - G7 - Cm
With Tritone Sub
Dm7b5 - Db7 - Cm
Classic minor substitution. Db7 resolves down a half step to Cm.
Bass: D - Db - C

Tritone Substitution by Genre

GenreHow It Is UsedExampleFrequency
Bebop JazzCore harmonic vocabulary. Used on every dominant chord.Charlie Parker, Dizzy Gillespie - ii-V-I with constant subsConstant
Neo-SoulSingle substitution for color on a cadence or loop.Robert Glasper, Thundercat - one sub per phraseOccasional
R&B / FunkTritone approach on V chord to I before groove resets.D'Angelo - dominant subs on turnaroundsOccasional
Lo-Fi Hip-HopSample chops that happen to contain tritone subs from jazz records.Many lo-fi beats sampled from 1950s-60s jazz recordingsAccidental/sampled
Film ScoreChromatic bass movement for tension without full dissonance.John Williams, Bernard Herrmann - tritone subs in suspense cuesDeliberate tension tool
Gospel / Contemporary GospelTritone approach on V to I for dramatic resolution.Choir arrangements with chromatic cadencesOccasional

Using Tritone Substitution in Your DAW

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Piano Roll: Swap the Chord

In your Piano Roll, select the dominant 7th chord block. Delete the root (leave 3rd, 5th, b7). Move the root note 6 semitones up or down. Rebuild the chord on the new root with 3rd, 5th, and b7.

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Update the Bass Track Separately

Keep the upper voices (3rd, 5th, b7) but move the bass note to the tritone sub root. The inner voices often need minimal movement since two of them are already in both chords.

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Detect Key First

Before adding subs, use BeatKey to detect the key of your sample or reference track. Knowing the key tells you which chord is the V (dominant) chord, which is the most natural place to apply a tritone sub.

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Use Chord Finder to Identify Existing Chords

Upload your audio to BeatKey Chord Finder to see the current chord progression. Identify any dominant 7th chords in the result. Those are your tritone sub targets.

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Altered Scale on the Sub

For jazz improvisation or melodic writing, the Altered Scale (7th mode of melodic minor) works perfectly over both the original dominant and its tritone sub. Over Db7 resolving to Cmaj7, use Db Altered (= D melodic minor).

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Watch for Key Clashes

The tritone sub introduces notes outside the home key (e.g., Db, Ab, Cb in G7's sub Db7 when you are in C major). Chromatic notes create tension before resolution. This is intentional in jazz, but check that your melody notes agree or intentionally clash.

Related Chord Theory

Find Dominant Chords in Your Audio

Before applying tritone subs, detect what chords are already in your sample or loop. BeatKey Chord Finder analyzes your audio locally in the browser.

1. Detect the Key
Upload sample to BeatKey. Get BPM and musical key instantly.
beatkey.app
2. Find the Chords
Run Chord Finder to see the chord progression. Identify dominant 7th chords.
chords.beatkey.app
3. Apply the Sub
Use the table above to find the tritone sub. Swap the chord in your DAW Piano Roll.
Count 6 semitones up

The BeatKey Tools Suite

Frequently Asked Questions

What is a tritone substitution?
A tritone substitution replaces a dominant 7th chord with another dominant 7th chord whose root is a tritone (6 semitones, augmented 4th) away. For example, G7 can be replaced by Db7 because both chords share the same tritone interval (B and F) between their 3rd and 7th. The resolution to the tonic is preserved because those two notes still want to move to C and E.
Why does tritone substitution work?
It works because the 3rd and 7th of a dominant 7th chord are shared between the original chord and its tritone sub (with their roles swapped). In G7, the tritone is B (3rd) and F (7th). In Db7, the same B and F appear as the 7th (Cb = B enharmonically) and 3rd respectively. The resolution tension is identical. Meanwhile, the bass note moves by a half step instead of a perfect 5th, creating smoother chromatic voice leading.
What is the tritone substitution of G7?
The tritone substitution of G7 is Db7. G to Db is exactly 6 semitones (G - Ab - A - Bb - B - C - Db). Db7 = Db, F, Ab, Cb (B enharmonically). In a Dm7 - G7 - Cmaj7 progression, replacing G7 with Db7 gives Dm7 - Db7 - Cmaj7. The bass walks D - Db - C (three consecutive half steps), which feels smoother than the original D - G - C leap.
How do I use tritone substitution in a DAW?
In your DAW Piano Roll, identify the dominant 7th chord (usually the V chord in your progression). Count 6 semitones up from its root to find the tritone substitute root. Rebuild the chord as a dominant 7th on the new root (1, 3, 5, b7). Update your bass track separately to move to the new root. Use BeatKey to detect the key of your sample first, then Chord Finder to identify existing dominant chords before adding substitutions.