A# Augmented
Introduction
Enharmonic equivalent: A♯ is enharmonically equivalent to B♭. See Bb Augmented.
Notes
A# Augmented Inversions
| Position | Notes |
|---|---|
| Root Position | A#4 – D5 – F#5 |
| 1st Inversion | D5 – F#5 – A#5 |
| 2nd Inversion | F#5 – A#5 – D6 |
Key Signature
The key of A# Augmented has Key signature data not available.
Theory: Intervals
The A# Augmented is built by stacking intervals from the root note. The formula R-M3-A5 describes the scale degrees used. The intervals P1-M3-A5 show the distance between each note in the chord.
A# Augmented — Frequently Asked Questions
What notes are in the A# Augmented chord?
The A# Augmented chord contains three notes: A# (root), C## (major third), and E## (augmented fifth — one semitone higher than a perfect fifth). The augmented fifth is what gives this chord its tense, unresolved quality.
How does the A# Augmented chord differ from A# Major?
The only difference between A# Augmented and A# Major is the fifth: A# Major has a perfect fifth, while A# Augmented raises it by one semitone to an augmented fifth (E##). This single change transforms a stable, resolved chord into one full of tension and forward motion.
What is the symbol for the A# Augmented chord?
The A# Augmented chord is written as A#aug or A#+. The "aug" or "+" symbol indicates the augmented fifth. In lead sheets and chord charts, both notations are common — A#aug appears in classical and jazz contexts while A#+ is common in pop and rock.
How do I use the A# Augmented chord in music?
Augmented chords create tension and a sense of motion. The most common uses are: (1) as a chromatic passing chord between the I and IV chords (e.g., A# → A#aug → IV), (2) over a chromatic bass line moving upward, and (3) in jazz as a substitute for dominant chords. The augmented fifth wants to resolve up by one semitone.
What are the inversions of the A# Augmented chord?
The A# Augmented chord has a unique property: all three of its inversions are enharmonically equivalent. Because each note is separated by exactly 4 semitones (a major third), rotating the notes always produces the same interval structure. A#aug in root position, first inversion, and second inversion all sound the same quality.
What songs use augmented chords?
Augmented chords appear in Oh! Darling (Beatles), which uses Aaug as a chromatic passing chord, and in many jazz standards as chromatic dominant substitutes. Stevie Wonder and Elton John frequently use augmented chords for their characteristic tension-building quality.
Practice Tips
- Compare A# Major and A# Augmented back to back — press A#–C##–(perfect 5th) then A#–C##–E## to hear how the raised 5th creates tension.
- The augmented fifth (E##) wants to resolve upward by one semitone — practice A#aug → resolving chord to feel this motion.
- All augmented chord inversions sound the same quality — explore this by playing root, first, and second inversions in sequence.
- Use A#aug as a chromatic passing chord: A# Major → A#aug → (IV chord) to hear its most common musical function.
- Augmented chords divide the octave into three equal parts — A#aug, C##aug, and E##aug are all the same chord (enharmonic). Verify this by playing each.
- In jazz, try using A#aug as a substitute for the V7 chord — the aug5 acts as a chromatic approach to the I chord's root.