Does the position of the recording device make a huge impact on the recording? For example if I was being recorded with the device situated on a tripod on a table (i.e. very high up), would that make much difference to if it was being held by a person say 10 metres from the piano?
For all of those who have weighed on this particular post and many, many other posts ON THIS VERY SAME SUBJECT, BEFORE!, I proffer the following:
1) Is the piano that you are playing on availed itself to you or yours at no cost? The answer is no!
2) Is the room, studio or hall you are recording in available at no cost? The answer is: maybe, or maybe not.
3) Therefore, find yourself an audio tech, of which there are a plenty because rock and roll and classical recordings are exactly the same. Sound is sound, and volume and volume is the same.
3) The computer digitalized recording of such is also the same, especially in terms of the "mix." However, the sound and the film must be recorded separately.
So, look around (they are there) for an audio tech, and then spend the money (not a lot) to make a good recording, with the film being also of the same quality (so it can be "mixed").
And, please record all of this on your own HD camera specific exactly to what they are doing for yourself.
I have "walked a mile in your shoes," and therefore I have lived this experience. Frankly, if done correctly, it is pure joy!
Go for it!