Where's the best place to sit (sound wise) for a live piano concerto?

The more expensive seats the better. Due to physics and acoustics of the building, if you are looking for sound quality, the definitely the expensive seats. Believe it or not, some seats up close are cheaper than some seats farther back because the seats farther back will give you a higher quality of sound. This is due to the acoustics. Sound waves have constructive and destructive waves. Constructive are when two waves overlap and have a frequency positioning of a whole number and the sound is augmented , while destructive waves have frequencies that overlap at 1/2 multiples of whole numbers, reducing the sound. The people who construct the auditorium have figured this out and made the adjustments, so that the more expensive seating will have better sound quality. Don't buy a seat up close because it's cheaper and you think it'll sound better. It actually sounds worse than expensive seats farther back.

As for the visual part, pick an area where you can see the pianist's hands, so on the left side of the auditorium.

Sergei Rachmaninoff wrote:

Rachmaninoff's Piano Concerto No. 2,

..... so he ought to know.

It is well known that he believed the best place to sit was centrally, and within arms' length reach of the keyboard.

Having said that, he did have very long arms.

I've always preferred the centre front rows of the first balcony in most concert halls for the best sound. You get a good balance of the whole orchestra and soloist. A little left of centre will give you a better view of the soloist's hands. That said, I was happy to hear Sviatoslav Richter from behind a pillar!

You probably won't notice that much of a difference, but I would say being closer will give you a more immersive experience. You still want to be able to see the orchestra.

To the left of the keyboard (facing the stage) so you can see the pianist's hands

front seats