Is it possble to remove piano sound from an orchestra conerto recording?

No.

Christian

You can get the 'music minus one' concertos. Concerto with orchestra only CD to practise with.

good luck
Bronnie

As noted above, it's not possible to remove it, but it is possible to reduce it somewhat, using a similar kind of sophisticated DSP (digital signal processing) that's used to reduce noise in old or poor recordings. You could check out software made for this purpose, but it's a very long shot that you'd get the kind of results you imagine. Your best bet is probably the preceding suggestion.

I doubt it would work at all. It sometimes works in pop music when the vocal is basically mono panned center, but that's never going to be the case in a classical recording like that.

If by "at all" you mean enough to be useful, perhaps, but what I had in mind was something like Digidesign's DINR. It allows the user to create a sonic "signature" of the "noise", which broadly is whatever you don't want.

I don't think noise reduction would work, it generally works best with things like air conditioning where it is a steady state of frequencies. Piano is the full frequency range, it probably wouldn't be able to take out much without taking out a lot of other stuff. But you can always try it out.

Even with Melodyne DNA it is not really possible to get anything close to a clean result...

Maybe into a future version of melodyne DNA, but what would be the use of implementing this function anyways.