That’s a good question. A piano is just like a harp…each one will have a different sound, even within a brand.
I wouldn’t recommend a Steinway. They are specifically designed as a solo instrument, to have an incredibly brilliant tone, and to an extent, will override the harp’s dynamics (even a L&H 23). Steinways are generally tuned ever so slightly flat in the bass and sharp from middle C upwards to give it the famous crystal-clear sound.
I would also recommend avoiding Yamaha, as they tend to have a bright (occasionally harsh) sound that would also compete with your harp. Yamaha pianos are known to sometimes lose their tune faster than others, due to the construction/wood.
Mason and Hamlin pianos have a very even and beautifully warm tone across the entire keyboard. They have a special steel support in the frame (called the crown retention system) that will greatly diminish the bowing of the soundboard over time. As my piano teacher said, “Mason and Hamlin will be the kind of piano that will last a lifetime. You’ll end up passing it on to your children.”
Young Chang makes a very good piano as well. Slightly more bright from my experience. My teacher has a Knabe that she took everywhere when she gave concerts around the South. It has lasted so well over the many years; in my own opinion the bass on hers is slightly weak, but overall, it’s a good choice as well.
I’ve never had the blessing of playing a Bosendorfer, but know that they are an excellent, quite historic Viennese piano. The largest model actually has a extended keyboard, 97 keys.
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