I'm not an expert, but I think you'd want something resiliant to absorb some of the sound, especially given the vaulted wood ceiling.

Since you've ruled out carpet, that pretty much leaves cork. The Glue down tile has more give than the floating. I'd be very careful moving a piano in, though: there's another thread here about flooring under the piano, and I don't think anyone has offered any definitive proof on whether it's advisable or not...

Thanks for your input. Yes the piano question was my post also....same room. I was just wondering about the acoustic concern and was hoping someone would have more information that would be helpful. A good Cork floor may be pretty expensive but it might be my only option.....considering everything. Hopefully the piano wont have to be moved too much.

Thanks again,

Here is a thought, If you are going to use this as a concert Hall, I would think that the amount of people in the room will absorb sound. Also any curtains that will be on the windows. I remember watching a This Old House episode, where they were redoing a floor at a concert hall, maybe the Philharmonic. I believe they were restoring the birch flooring.

I think most people prefer a hard floor in a large piano room, but it is entirely a matter of personal taste.

A hard floor gives you more flexibility to tune the sound because if it is too bright you can add area rugs, draperies, etc.