Open A Tuner
Tune your guitar to Open A (E A E A C♯ E) using your microphone. The tuner below is already set to Open A — press Start Recording and strum.
String-by-String Frequency Chart
These are the exact target frequencies this tuner listens for, at A4 = 440 Hz equal temperament. String 1 is the thinnest (highest) string.
| String | Note | Frequency |
|---|---|---|
| 6 | E2 | 82.41 Hz |
| 5 | A2 | 110.00 Hz |
| 4 | E3 | 164.81 Hz |
| 3 | A3 | 220.00 Hz |
| 2 | C♯4 | 277.18 Hz |
| 1 | E4 | 329.63 Hz |
Before You Tune Up
Open A raises three strings, which means more tension than standard tuning, not less. Raise each string gradually and stop the moment the needle centres — a string being tightened gives no warning before it breaks.
If you want Open A's pitches without the added load, tune to Open G and capo the 2nd fret. Same notes, same shapes, less strain on the instrument.
How to Use This Open A Tuner
- Press Start Recording on the tuner above and allow microphone access.
- The Open A preset is already selected.
- Leave strings 6, 5, and 1 alone. E, A, and E are already correct.
- Raise string 4 from D to E (164.81 Hz) — a whole step up.
- Raise string 3 from G to A (220.00 Hz) — another whole step.
- Raise string 2 from B to C♯ (277.18 Hz). This is the third of the chord, so tune it to exactly 0 cents.
- Strum all six for an A major, then run a second pass.
What is Open A Tuning?
Open A tunes the open strings to an A major chord. The form on this page — E A E A C♯ E — keeps the low E where it is and raises the middle of the instrument, which produces a bright, tightly strung sound well suited to electric slide.
Be aware that "Open A" names two different tunings in common use. The other is Open G moved up a whole step (A E A C♯ E A), reached by raising all the Open G strings. Both sound an A major chord; they voice it differently and the shapes are not interchangeable. Older blues tabs usually mean the second.
Why Use Open A?
- Bright slide tone: Higher tension gives a harder attack and more sustain under a slide than the looser open tunings.
- A is a natural blues key. Much of the blues repertoire sits in A, and an open tuning in the song's key means the open strings are always consonant.
- One-bar chord changes: Barre the 5th fret for D, the 7th for E. The I-IV-V of a blues in A is three positions.
- Ringing drones: Doubled A and E strings let you hold open drones under a melody.
Slide Positions in Open A
- Open: A major
- 5th fret: D major (the IV)
- 7th fret: E major (the V)
- 12th fret: A major, an octave up
Troubleshooting
A string broke while tuning up. Most likely string 3, moving a full whole step. Use a fresh set and go up in small increments, or drop a gauge.
The chord sounds sour. Check the C♯ on string 2 — it is the only third in the voicing, so any error there colours the whole chord.
The neck feels different and it buzzes. Added tension increases forward bow. A small truss rod adjustment fixes it if you stay in Open A.
Related: Open G (the safer route to these pitches with a capo), Open E (the same raised-tension idea), and the full guide to alternate guitar tunings.
Frequently Asked Questions
What are the notes in Open A tuning?
This version of Open A is E A E A C♯ E from lowest to highest. Strumming the open strings sounds an A major chord.
Which strings change from standard tuning?
Three strings are raised: the 4th string D goes up a whole step to E, the 3rd string G goes up a whole step to A, and the 2nd string B goes up a semitone to C♯. Strings 6, 5, and 1 stay as they are.
Is there more than one Open A tuning?
Yes, and it causes constant confusion. This page uses E A E A C♯ E, the raised form. The other common version is Open G tuned up a whole step — E A E A C♯ E's relative, written A E A C♯ E A. Slide players often mean the second. Check which one a tab intends before you retune.
Does Open A put extra tension on my guitar?
Yes. Like Open E, this tuning raises three strings rather than lowering them, so total neck tension increases. Tune up gradually, and consider one lighter gauge if you keep a guitar in Open A. The safer route is Open G with a capo at the 2nd fret, which gives the same pitches at lower tension.
What is Open A good for?
Slide blues, primarily. The raised strings give a bright, tight response that cuts through a band, and as with any open tuning a slide barred across any fret produces a major chord at that position.