These days many people enquire about A440 tuning for their harmonium. We will attempt, herein, to clarify these issues. Simply put, most harmoniums that arrive from India are not at A440, there is no reason for them to be, and there are probably more reasons not to seek out an A440 tuned harmonium than there are to seek one out. A harmonium tuned to A440 is not "more in tune" than a harmonium tuned to A432, A442, or A445.5. What is most important is that the harmonium be in tune with itself.

History of A440 tuning

Up until the 19th century there wasn't much attempt in Europe to standardize pitches. Concert A could vary from A380 to A480 - a huge range. Gradually the idea of standardization took hold, focusing usually around A443 -44. In the US and Britain today the standard is A440 but in Europe it is A442-443.

The harmonium in India

The harmonium (a foot pumped organ) was invented in France and came to India with the English colonialists and missionaries. It was gradually adapted for Indian music by putting it on the floor and changing it so it was pumped with one hand and melodies and simple chords could be played with the other hand.

Indian music does not involve large orchestras of different instruments, so there was never any impetus to standardize pitch. SA (the root) can be fixed at any pitch, and all other notes are relative to that. The harmonium itself was a controversial addition to Indian music, but is now widely accepted and used primarily as vocal accompaniment, Since stringed instruments and Indian hand drums are tunable, ensembles with a harmonium will simply tune to the harmonium. 

In the past most harmoniums were quite a bit sharp of A440 - tending to be in the A442-445 range. This reflects the older European standard and the above mentioned unimportance of any fixed standard. In the past decade there is increased demand in the West for harmoniums at A440, so most makers have tried to accommodate that. It is still rare to receive a harmonium from India that is exactly at A440. This is because of lax standards, and also the fact that reeds change pitch with temperature. As they get cooler they go up in pitch. So a harmonium tuned nicely to A440 in muggy, hot India and shipped to California, may arrive at A441 or above. Also the larger bass reeds will change proportionally more, so the whole instrument will tend to need a tuning overhaul when it gets here.

We tune all the harmoniums that we sell (unless they are labeled "factory tuned"). First we check where all the reeds are tuned, and then tune them all to a common mean. The idea is to change the pitch of the reeds as little as possible and still have all the octaves and unisons match. Reeds take a while to settle, and tend to want to go back to where they were before, so changing the pitch of reed more than 5 cents often requires several tunings over several days. This is "hand tuned". The pitch could be 441, 442 or 439.5 or anything, as long as it is consistent throughout the instrument.

Do I need A440 tuning?

If all that is clear, now you must decide if you really want an A440 instrument. You should consider this if:
-- You are playing with fixed pitch instruments like a piano or silver flute that can't tune to the harmonium.
-- You are playing with guitar players or the like who refuse to tune to anything but their fixed electronic tuners.
-- You are doing a professional recording with fixed pitch instruments.

Otherwise there is really no reason to bother. In fact there are many arguments against the A440 tuning.
-- Most harmoniums are not at A440, so if you playing with friends, chances are their harmoniums are sharp and your A440 won't match.
-- Reeds take a while to settle, and want to drift back to where they originally stood. So if someone takes an A442 harmonium down to A440, it will probably drift back up a little. When we sell a guaranteed A440 harmonium we tune it once, let it sit a day, tune it again, and continue until the tuning remains stable.  That's why we charge an extra $125.
-- They usually cost more.

Keep in mind that reeds change pitch depending on how hard you pump. You can change the pitch of any note at least several cents by pumping harder or softer. Also, as mentioned above, the reeds change pitch a little bit with climate conditions.