Best speaker/system piano concerts

Aside from the investment in the speakers and the associated gear, you need to make sure the speakers are set up properly in the room and the room acoustics are properly selected. As Wolf said, many "good" systems can reproduce the piano but in my experience, recreating the soundstage that can accurately reflect the size and the location of the piano is a bigger challenge. Furthermore, the "sound" of piano can vary significantly depending on how its recorded, live or in the studio, and more specifically where the microphone(s) are placed. You'll find on the same recording, some speakers push the piano to the back of the soundstage and others bring it to the front. With that sort of cash layout, you just need to listen to different systems and decide which one resembles the "real" sound of piano better than others, in our room and to your ears. My 2 cents.

I would look more at the front end source.  You want something that can communicate with the rest of your system but has a natural tone with long, slow note decay that will let the notes just linger to give you the natural wood of the piano and provide the soundstage front to back dimension.

Happy Listening. 

"Personally, I do not like what warm sounding equipment does to the sound of a piano. Warmth is wonderful on vocals, guitars and certain instruments, but it beats against the stretched overtones of a piano. The overtones in a piano occur at slightly higher than harmonic ratios, and these create beat notes with the exact integer ratios produced by electronic equipment (and speakers). Too much harmonic distortion will make a piano sound out of tune."

That is quote from John Siau -  Director of Engineering in Benchmark Media Systems, Inc.

Snell Type AIII's are a forgotten classic design still competitive with today's big-buck speakers! Dead-flat response (+ and - 0 db) from 30 to 20k and wide dynamic range. Plus textbook perfect off-axis response! Lowest coloration possible from a dynamic speaker!