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Reference guideA440, concert pitch and pitch raising: what the terms mean.
Concert pitch means A4, the A above middle C, vibrates at 440 cycles per second. It is the reference that lets a piano match other instruments and that keeps the music in its intended key. A piano that has been sitting untuned may be well below this standard, and restoring it involves more than an ordinary tuning.
Published 23 October 2026 · 3 minute read · Written for buyers, not for any one instrument
One note, one number, one reference.
A440 means the note A4 (the A above middle C) vibrates at 440 hertz. This is the international standard reference pitch, used by tuners, orchestras and instrument makers worldwide. When a piano is tuned to A440, every other note is set in relation to it. The result is an instrument that can play with other standard-pitched instruments and that sounds in the key the composer intended.
The Piano Technicians Guild notes that keeping a piano at standard pitch gives it its best power and tonal range, supports ear training, and helps the instrument stay in tune over time, because the strings are at the tension the maker designed for.
Strings lose tension, and humidity helps.
A piano has roughly 220 strings under tension. Over time, strings stretch and wooden parts settle, and the pitch drops. Two factors accelerate this:
- New instruments: the strings stretch and the soundboard settles in the first year or two. Manufacturers generally advise more frequent tuning in this period.
- Humidity: the wooden soundboard swells when humidity rises, increasing string tension and pitch. It shrinks when the air dries, lowering tension and pitch. Because the drop in dry conditions is usually larger than the rise in humid conditions, the net effect over a year without tuning is a fall in pitch. Actual room conditions vary, so observe the environment and ask the technician what applies to the instrument.
A piano tuned regularly stays closer to A440 because each adjustment is small. A piano left untuned for years may sit well below standard pitch, and bringing it back is a different procedure from a routine tuning.
A rough pass before the fine tuning.
When a piano has dropped significantly below A440, a normal fine tuning cannot produce an accurate result in one pass. Tightening one string adds tension to the frame, which pulls the other strings out of the adjustment already made. With roughly 220 strings, the cumulative shift is significant.
A pitch raise brings all the strings up to their correct average tension first, in a deliberate rough pass. Once every string is approximately where it should be, the fine tuning follows. The small remaining adjustments do not disturb the neighbouring strings enough to spoil the result.
For a moderate correction, the pitch raise and the fine tuning can happen in one visit. A piano that has been very far below pitch for a long time may need the correction done in stages, because the instrument needs time to settle under the new tension before the next pass is stable. The technician assesses the instrument and explains what is needed for the specific piano.
Four things that help the assessment.
When booking a tuning or asking about pitch:
- When the piano was last tuned. If you do not know, say so. Label an approximate date as approximate; if it is unknown, say that it is unknown.
- What you have noticed. Does it sound flat against a recording? Do certain notes sound wrong together? Has it been moved recently?
- What the piano will be used for. Give the intended performance, recording or practice dates and the reference pitch agreed with any other performers. The technician must assess what adjustment and timing are appropriate.
- Whether it needs to match another instrument. If you are playing with a group, an ensemble or for a recording, tell the technician the reference pitch being used.
The tuning guide covers when to book, how to prepare the room, and what to expect during and after a tuning visit. The humidity and care guide covers how to reduce pitch drift between tunings.
Pitch and tuning, answered.
What is A440?
A440 means the A above middle C (A4) vibrates at 440 hertz, or 440 cycles per second. It is the international standard reference pitch. When a piano is tuned to A440, it can play with other instruments tuned to the same standard.
Why does a piano drop below concert pitch?
String tension decreases over time, especially if the piano is not tuned regularly. In Singapore, the soundboard swells in high humidity and shrinks in dry conditions, which changes the tension on the strings. A technician assesses the actual pitch and condition; do not infer the required correction only from the instrument’s age or location.
What is a pitch raise?
A pitch raise is a procedure that brings all the strings back up to their correct average tension before fine tuning begins. It is needed when a piano has fallen far enough below A440 that a normal tuning pass cannot produce an accurate result in one step, because tightening one string changes the tension on others already adjusted.
How many visits does a pitch raise take?
It depends on how far the pitch has dropped and how the piano responds. A moderate correction may be done in one visit alongside the fine tuning. A piano that has been untuned for many years may need the pitch brought up in stages. The technician can assess the instrument and explain what is needed. No fixed number of visits applies to every piano.
Is A442 a different standard?
Some orchestras and ensembles tune to A442 or other references for their own musical reasons. A440 remains the international standard. If you need to match a specific ensemble or recording pitch, tell the technician. The required reference belongs in the booking discussion; this guide does not establish Music Companion’s default pitch or promise a particular adjustment.
Where the rest is set out on this site: Tuning guide → Tuning, regulation and voicing → Humidity and piano care → Piano tuning services → All guides →
Need a piano assessed?
Tell us the make, model, when it was last tuned, and what you have noticed. We can explain what the instrument likely needs.