A#aug Chord on Piano
A#aug = A# – D – F# (Root, Major 3rd, Minor 6th)
Stack the augmented formula on A# and you land on A#-D-F#, a chord that sounds restless, built from two stacked major 3rds. A# itself is the last black key of the three-black-key group, just before B on the keyboard. Struck together in root position, A#aug comes out to a stretch a little beyond a fifth in root position, still manageable for most adult hands. Functionally this is an altered V+ pulling toward A# major's tonic, or a whole-tone color chord that avoids the perfect 5th entirely, and with the 5th raised a half step, the chord loses its stable perfect fifth entirely, so it almost always keeps moving rather than landing. Count them and it's 3 notes including the root, which is useful to know before comparing it against a written-out voicing.
Think of A#aug primarily as an altered V+ pulling toward A# major's tonic, or a whole-tone color chord that avoids the perfect 5th entirely — that's the job it does most often, on paper and by ear alike. Move A# up an octave and D becomes the bass note — that's first inversion; push again and F# lands on the bottom for second inversion. Neither is optional to know if you want to read a lead sheet fluently. Most adult hands can cover this shape without stretching, which is exactly why it's worth practicing hands-separately first rather than jumping straight to a moving bass line underneath it. It shows up regularly in jazz reharmonization of a dominant chord just before it resolves, and again in musical-theater transition chords. With the 5th raised a half step, the chord loses its stable perfect fifth entirely, so it almost always keeps moving rather than landing. Since last black key of the three-black-key group, just before B, a black-key root asks the hand to angle slightly forward, a small adjustment that stops feeling foreign after enough repetition. Playing alongside a bass instrument, the left hand usually simplifies down to the root (or root plus fifth) while the right hand handles the full triad — doubling every note in both hands just thickens the texture without adding much. Middle-of-the-keyboard is the default zone for comping this shape, but the identical notes read completely differently elsewhere — drop two octaves and it feels like a bass hit, climb two octaves and it turns light and bell-like. With enough repetition, A#aug becomes recognizable by sound alone — restless, built from two stacked major 3rds is the giveaway most players learn to listen for before they've even placed their hands on the keys.
Voicings
Root Position
First Inversion
How to Practice It
Treat root position as the starting point, not the finish line: right hand fingers 1-3-5, played block-style until every note in A#aug sounds simultaneous rather than smeared. Most adult hands can cover this shape without stretching, which is exactly why it's worth practicing hands-separately first rather than jumping straight to a moving bass line underneath it. Bring in a bare left-hand root once that's solid, then combine hands slowly with a metronome before pushing tempo. The real test is moving cleanly from a neighboring chord into A#aug and back — practice that specific motion on its own, separate from playing the chord in isolation. The raised 5th is easy to underplay or bend back toward a natural 5th out of habit; hold it deliberately sharp or the chord collapses into a plain major triad.
Common Progressions
- A#aug as an altered V+ resolving into A# major's tonic
- I – I+ – vi: A#aug used as a chromatic passing chord in A# major
- A#aug as a whole-tone color chord before resolving down a half step
FAQ
- What notes make up A#aug on piano?
- Left to right, root position A#aug is A#, D, F#: A# on the bottom, then the augmented intervals stacked above it in order. Flip which note is lowest and you get an inversion of the same four (or three) notes.
- Is A#aug an easy chord to play on piano?
- Yes — three-note triads are about as approachable as piano chords get, sitting easily under fingers 1, 3, and 5. The only wrinkle with A# is that the root is a black key, which nudges the hand slightly forward.
- Where does A#aug typically show up in a chord progression?
- Most often as an altered V+ pulling toward A# major's tonic, or a whole-tone color chord that avoids the perfect 5th entirely. With the 5th raised a half step, the chord loses its stable perfect fifth entirely, so it almost always keeps moving rather than landing.
- What's the closest related chord to A#aug?
- Lower the raised 5th back down a half step and A#aug resolves into a plain major triad — the augmented 5th is the one altered note driving the whole restless color.
A#aug on other instruments: A#aug on Guitar. Related: how chords are built, chord finder.