A#aug Chord on Guitar
A#aug = A# – D – F# (Root, Major 3rd, Minor 6th)
A#aug stacks two major thirds on top of the root, giving it — like the diminished seventh chord but built from a different interval — a fully symmetrical structure. At the sixth-fret barre, that symmetry means A#aug shares its exact three notes with only two other augmented triads on the entire fretboard.
The notes are A#, D, F# — root, major third, sharp fifth. Because three stacked major thirds eventually return to the starting pitch class, A# augmented, D augmented, and F# augmented are all built from the identical three notes — only the note treated as the root differs. Musically the raised fifth gives the chord a restless, unresolved brightness quite different from a diminished chord's murkier tension; augmented triads push a major chord's fifth upward, often as a brief chromatic move into the following chord's root or third.
Fingerings
Barre (6th fret)
How to Practice It
Because A#aug, Daug, and F#aug are physically the same three notes, try naming the chord all three ways as you play it, then resolve it to a major chord built on each of those three roots to hear how differently the identical shape can be used. The raised fifth is the note to focus on by ear — it's the one pitch that distinguishes this chord from a plain A#/Bb major triad.
Common Progressions
- A# – A#aug – Eb (I – I+ – IV, using the raised fifth as a chromatic lead-in)
- F# – A#aug – A# (illustrating the shared-note relationship resolving to A#)
- Cm – A#aug – F#m (using the augmented triad as a connective chromatic chord)
- A# – A#aug – A#6 – A#7 (a classic ascending-chromatic-line cliché)
FAQ
- What notes make up A#aug?
- A#, D, and F# — root, major third, and sharp fifth, with the raised fifth being the note that sets it apart from a plain A#/Bb major triad.
- Why can A#aug also be called Daug or F#aug?
- An augmented triad is built from two stacked major thirds, and because three major thirds evenly divide the octave, the same three notes can be spelled starting from any of the three pitches involved.
- How does A#aug's symmetry compare to A#dim7's?
- Both are symmetrical, but A#dim7's minor-third stacking gives it four equally valid roots, while A#aug's major-third stacking gives it only three, since the two chords divide the octave differently.
- What's the typical use for an augmented triad in a progression?
- It's most often used as a brief chromatic passing chord, raising a major triad's fifth by a half step to create forward motion into the next chord.
- Is A#aug hard to finger compared to plain A#/Bb major?
- It's a similarly compact barre shape, generally no harder than the plain triad, though the raised fifth changes which finger lands where.
- Does A#aug appear naturally in the A#/Bb major scale?
- No — augmented triads aren't diatonic to the major scale in standard practice; A#aug is reached by raising the fifth of a plain A#/Bb major triad for a specific chromatic effect.
- How does the ear typically perceive an augmented triad?
- As bright but unsettled — the raised fifth keeps the chord from resolving the way a plain major triad does, giving it a slightly eerie, suspended quality.
- How is an augmented triad different from a major chord with a sharp ninth added?
- They're unrelated — a sharp ninth decorates an otherwise ordinary major triad from above, while an augmented triad alters the fifth itself, changing the chord's basic character rather than just adding a layer of color.
- Do augmented chords appear often in traditional folk or bluegrass guitar playing?
- Rarely — their symmetrical, chromatic character suits jazz, classical, and pop songwriting that wants a moment of harmonic surprise, more than the diatonic vocabulary typical of folk and bluegrass.
- Is there a quick way to confirm an augmented triad's fingering is correct?
- Play the raised fifth against the root by itself — it should sound like a slightly stretched major third rather than a clean perfect fifth, confirming the shape is genuinely augmented and not accidentally plain major.
- Do augmented chords ever serve as an entire song's harmonic basis?
- Rarely as a full song's foundation, though some experimental and psychedelic material leans on augmented harmony far more heavily than typical pop or rock does.
- Is the augmented triad's symmetry exploited the way dim7's is?
- Yes, though less often — since it divides the octave into three equal parts rather than four, it offers fewer alternate-root options than a dim7 chord but still allows some similar chromatic reinterpretation.
A#aug on other instruments: A#aug on Piano. Related: how chords are built, chord finder.