Lesson 23 · All 12 keys

Augmented 7th Chord Trainer

Learn how an augmented 7th chord is built one semitone-count at a time — a dominant 7th chord with its 5th raised a semitone — then put it to work with three MIDI exercises: playing all 12 augmented 7th chords around the circle of fourths, and 5 jazz plus 5 gospel chord progressions that show off its extra "altered dominant" pull, in every key.

What is an augmented 7th chord?

This chord goes by many names, all describing the exact same four notes: augmented 7th, 7♯5, +7, dominant 7♯5, C7♯5, C+7, C7+, augmented dominant seventh, and dominant seventh augmented are all the same chord — a plain dominant 7th chord with its 5th raised a semitone.

An augmented 7th chord is a 4-note chord — an augmented triad with a minor 7th stacked on top. Every augmented 7th chord — in any of the 12 keys — is built the exact same way, by counting semitones to the right from a root note:

  1. Start on the root — the note that names the chord.
  2. Count 4 semitones to the right to land on the major 3rd.
  3. From there, count 4 more semitones to the right (8 semitones from the root) to land on the augmented 5th — a semitone higher than a perfect 5th.
  4. From there, count 2 more semitones to the right (10 semitones from the root) to land on the minor 7th — the same 7th a plain dominant 7th chord uses.
Example — C augmented 7th (C7♯5): start on C, count 4 semitones right to reach E, 4 more to reach G♯ (not G — that's the raised, augmented 5th), then 2 more to reach B♭. C‑E‑G♯‑B♭ is the C7♯5 chord. The pattern 4, 4, 2 (10 semitones total from root to top) is what makes a chord "augmented 7th" — every one of the 12 augmented 7th chords is this same shape, just moved to start on a different key.
Compare this to a plain dominant 7th chord (Lesson 13), whose pattern is 4, 3, 3 — root, major 3rd, perfect 5th, minor 7th. An augmented 7th chord raises that perfect 5th a semitone, pulling it outward instead of leaving it settled. That extra tension is exactly why jazz and gospel players reach for it as a spicier, "altered dominant" substitute for a plain V7 anywhere a dominant chord resolves down a 5th (or up a 4th) to its tonic — the raised 5th wants to keep climbing, adding even more pull toward the chord that follows.

Try it: pick a root and build the chord step by step

Step 1 of 4
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Chord toneNoteSemitones from rootMIDI #

All 12 augmented 7th chords at a glance

ChordRoot+4 semitones → 3rd+4 semitones → ♯5th+2 semitones → ♭7th

This MIDI exercise plays all 12 augmented 7th chords, one after another, moving around the circle of fourths — each chord's root sits a perfect 4th (5 semitones) above the last one: C → F → B♭ → E♭ → A♭ → D♭ → G♭/F♯ → B → E → A → D → G → back to C. Every chord is played as a full 4-note augmented 7th chord (root, 3rd, ♯5th, and ♭7th together).

Chord 1 of 12
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The 12 chords, in circle-of-fourths order

#ChordRoot3rd♯5th♭7th

Five jazz chord progressions that put the augmented 7th chord to work — almost always as a spicier, altered substitute for a plain dominant 7th. Pick a progression and play it in one key or cycle through all 12.

Key of C
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Progression in C

DegreeChordNotes

Five gospel chord progressions built the same way. Pick a progression and play it in one key or cycle through all 12.

Key of C
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Progression in C

DegreeChordNotes