A Major Scale
Notes: A – B – C# – D – E – F# – G#
A major spells out A, B, C♯, D, E, F♯, and G♯ — three sharps — and it holds a distinction unlike any other key on this site: its tonic is literally the pitch orchestras and bands the world over tune to before a single downbeat is played. Concert pitch A440 isn't an arbitrary convention picked at random; it's this exact note, meaning every time a symphony oboist sounds an A for the ensemble to match, or a guitarist checks a tuner before a gig, they're reaching for the exact same pitch that anchors this entire scale from its very foundation.
On guitar, the open A chord (x02220) is one of the very first shapes most beginners learn, needing only three fingers bunched together on the second fret, and it pairs with an equally friendly open E to form the backbone of countless three-chord songs. The full A major scale isn't quite as open-string-drenched as D or G, but the open A and open E strings still anchor it at both the root and the fifth, giving even a fretted-heavy run through this key some resonant low-end support. Mandolins and violins both tune a string to A as well (the violin's second string, the mandolin's third course), which is part of why A major turns up so often in folk, bluegrass, and old-time string band music — it's a key where fiddle, mandolin, and guitar can all lean on an open or lightly fretted A simultaneously. Country and western swing bands built entire dance-hall repertoires around A specifically because it let every string instrument in a typical lineup — guitar, mandolin, fiddle, and often bass — share resonant open-string territory at once, producing a fuller ensemble sound than a more mismatched key would allow. On piano, three sharps sits at a moderate level of visual density, comfortable for an intermediate player without tipping into the genuinely dense sharp keys like B or F♯ major. Because A is the universal tuning reference, it's also the key many musicians use instinctively to check whether an instrument is in tune with itself before worrying about anything more complex. Wind and brass instruments outside the guitar and piano world lean on A too — many concert bands and orchestras tune an entire ensemble to a single sustained A before a performance begins, meaning this scale's tonic is quite literally the first pitch a listener hears, even before the actual music does.
Chords Built From This Scale
The diatonic triads of A major are A major (I), B minor (ii), C♯ minor (iii), D major (IV), E major (V), F♯ minor (vi), and G♯ diminished (vii°). A, D, and E are all comfortable open-position guitar chords, making the A-D-E cycle (I-IV-V) a direct cousin of the equally beloved E-A-B and D-G-A families covered elsewhere on this site — three open chords, minimal left-hand strain, and an enormous share of blues, rock and roll, and country repertoire built from exactly this combination. F♯ minor, the vi chord, typically needs at least a partial barre, but the A-F♯m-D-E cycle turns up so constantly across early rock and roll and pop recordings that most players end up learning it earlier than its difficulty alone would suggest. B minor and C♯ minor round out the family, both usually played as barre shapes, and while they demand more left-hand work than A, D, or E, they appear often enough in bridges and pre-choruses that a working guitarist eventually needs them regardless of how comfortable the rest of the key feels. Country and bluegrass rhythm players also frequently reach for A7 as a substitute for the plain tonic chord in a turnaround, since the added flat seventh sharpens the pull toward D without demanding any new fingering beyond the open A shape already in hand. Songwriters working in A also lean on the E-D-A cadence (V-IV-I) at the end of a phrase almost as often as the more familiar I-IV-V ordering, since reversing the direction of that same three-chord family produces a noticeably different, more circular sense of resolution than the forward-driving push of the standard ordering.
How to Practice It
Begin with the open A and E chords, since they anchor this scale's most common guitar context, and practice switching between them quickly before adding D into the mix to complete the I-IV-V cycle. Once that's comfortable, work out the full seven-note scale using the open A and E strings as reference points, filling in the remaining five notes with fretted notes on the neighboring strings — this hybrid approach (open strings for the root and fifth, fretted notes for everything else) is a genuinely useful way to internalize how A major's geography differs from a fully open key like G or a fully fretted key like F. Since A440 is the universal tuning reference, use this key specifically to practice tuning by ear: play the open A string, then sing or hum the pitch back, and compare it against a tuner to build a genuine internal sense of what standard pitch actually sounds like. Over time, try recalling that same pitch from memory before ever touching the string, then checking yourself against the tuner afterward — professional musicians who claim reliable pitch memory usually built it through exactly this kind of repeated, deliberate daily practice, rather than through any innate gift they were simply born already possessing. On piano, treat the three sharps (F♯, C♯, G♯) as a connected group and drill the A-D-E chord progression in the left hand while running scale fragments in the right, since that combination mirrors how the key gets used in real folk and country piano accompaniment. It's also worth working the A-F♯m-D-E cycle into a fingerpicking or strumming pattern of your own, since decades of recorded rock and pop have built entire careers on those same four shapes. Try tuning purely by ear before reaching for an electronic tuner every so often too, using the open A string as your one fixed reference point — that habit builds a genuinely reliable internal sense of pitch that a device alone can't teach you. If you sing, spend a few minutes matching your own voice to the open A string as a standalone daily exercise, since that pairing of instrument and voice around one shared reference pitch is a foundational ear-training habit many working musicians maintain for their entire careers.
FAQ
- Why is A major associated with tuning specifically?
- Concert pitch A440 (440 Hz) is the internationally standardized reference pitch most orchestras, bands, and electronic tuners use, and it's literally the note A — so every time a musician tunes an instrument to that reference, they're tuning to the tonic of this exact scale.
- What's the relative minor of A major?
- F♯ natural minor. Both keys share the exact same three sharps and the exact same seven pitches — an A major fingering you already know doubles as an F♯ minor fingering the moment your ear shifts its sense of home over to F♯.
- Why do bluegrass and old-time string bands favor A major?
- Violin and mandolin both tune a string directly to A, giving fiddlers and mandolin players an open-string anchor in this key that guitarists share too through the open A string, letting an entire string band lean on shared open-string resonance at once in ensemble playing.
- Is F♯ minor hard to play in A major songs?
- It's the trickiest of the common chords in this key, typically needing at least a partial barre, but it appears often enough in recorded A major music (the classic A-F♯m-D-E cycle especially) that most intermediate guitarists learn it fairly early despite the extra difficulty.
- How does A major compare to D and E major in guitar-friendliness?
- A sits in between the two — its open A and E chords are just as easy as anything in D or E major, but the full seven-note scale isn't quite as open-string-saturated as either neighboring key, landing A in a comfortable middle ground rather than at either extreme.
- Is A major common in classical violin repertoire?
- Yes, notably — the violin's own second open string is tuned to A, giving the instrument a natural resonant anchor in this key similar to how E major suits violin's highest string, and several well-known violin concertos and sonatas are written in A for that reason.
- Is there a reason method books teach A, D, and E together so often?
- All three keys share comfortable open-position tonic chords and interlock through the I-IV-V relationship — A is the V of D and the IV of E — so a student picking up open A, D, and E chords together unlocks an enormous cross-section of folk, blues, and rock repertoire almost overnight.
- Do wind and brass players tune to A too, not just string players?
- Yes — concert bands and orchestras commonly settle the entire ensemble on a single sustained A before a performance begins, meaning brass, woodwind, and string sections alike are all referencing this scale's own tonic before a note of actual music has been played.
Related: the major scale formula, scale visualizer, all scales.