"Standard" or "concert" pitch - what is it and is my piano tuned to it?

What is generally referred to as either standard or concert pitch is an absolute frequency to which a reference note is tuned on pianos or other instruments. The note which is always used as a reference is A above middle C (A49 on a piano), and the standard pitch for this note is 440Hz.

440Hz was agreed as a standard at an international conference in May 1939, and was adopted in 1955 by the International Standards Organization (ISO 16). It's used in most parts of the world, including Britain and North America; however some European countries (informally) use higher-pitch tunings such as A=444Hz.

Very often when out tuning I come across pianos that are a long way below this - sometimes a semitone or even a tone lower. Generally, these are older pianos where the pitch has drifted down over a period of many years of sometimes irregular tuning. To bring these pianos up to pitch requires the tuner to undertake two operations - firstly a fast rough tuning to get it close to the required level, then a fine tune to get the notes at exactly the right pitch. Because this is a more complex and time-consuming job than a standard fine tuning (just doing the piano once), most tuners will quite reasonably charge more money for the service.

If you have a piano that is well below standard pitch and you're having it tuned, the first question to ask is whether you would like it brought up to pitch. Any piano can be tuned perfectly well to itself, and leaving a piano below pitch does not damage it in any way, although the tone may arguably not be quite as good. What are the considerations for doing this?

There are some (generally older) pianos where a pitch raise may be inadvisable, due to the condition of the instrument (e.g. if the strings are rusty, there is a risk of breakages). A tuner should be able to advise on whether it is a sensible idea to attempt this, although it should be possible with most instruments in a reasonable condition.

Assuming the piano is OK to have its pitch raised, the following are important reasons for getting an instrument to pitch:
(i)    Playing with other instruments (which will be tuned to A440)
(ii)    Singing with the piano to a high standard
(iii)    Playing along with recordings.

If the piano is used solely for individual practice (or singalong-type singing), there is no imperative need for it to be on pitch, though many pianists prefer it to be nonetheless.

If I come across an instrument well below pitch, I will always ascertain the needs of the customer and check before carrying out a pitch raise. I am perfectly happy to tune a piano at a lower pitch (normally cheaper) if this is a better option for the owner. Additionally, if the piano is subsequently regularly tuned, there is an option to raise the pitch in small steps.

One point to note is that if a piano is already at standard pitch and kept regularly tuned (generally at least once a year), the tuner should "nudge" the tuning of the piano very slightly up as needed to keep it there; under these circumstances there's no excuse for the tuner to allow it to go flat.