I have a number of Deutche Grammaphon LP's but none of them are piano. Orchestra is so much easier to reproduce than piano, IMHO.
My favorite piano LP's are George Winston on Windham Hill Records. I have both the LP and CD of Winter. You can tell there is something special about the ping of the piano attack, and when I had MP3 capability for a month or two on this computer, the video was of him playing a Bosendorfer grand in Montana somewhere. The sound was as vile as ever on that MP3.
Mobil Fidelity Records has been quite amazing, although I only have the locomotive versions. They did remastering of the pop catalog, I've been on the lookout for them but there weren't any fans in Indiana I suppose, never saw one in a store. I do have some used Telearc LP's on pipe organ, and those are quite good. But you can't tell what a pipe organ is supposed to sound like as easily as you can grand piano.
RCA of the dynagroove era did some amazing recordings. I use Peter Nero CD Young and Warm and Wonderful as a speaker test. He plays a grand piano top octave solo for a few measures, and that causes many amps and speakers to produce vibrato, which is obviously stupid. RCA is an old brand however. If you buy RCA recordings from the fifties, they were very late to ditch the ribbon mikes they manufactured for the superior Neumann or Deutz Radio condensor mikes. Pity, they had Horowitz and Reubenstein under contract.
The US leader in superior sound starting 1955 was Mercury Records, especially albums engineered by C R Fine. I have a recording of Dupre playing a pipe organ in 1955 that is mono, but a great mike. later records engineered by Mr Fine were stereo. No piano LP's by him, however.
As far as listening to your MP3's, my op system reports shockwave has been hacked and should be replaced. No replacement is available for this 700 mhz Pentium 2 mainboard, and the sound quality of most of the MP3's I did listen to was so bad, I don't see the point of wasting $500 on a new computer. I sure as **** don't want a touch screen with my 200 WPM typing speed, and Windows 10 stops you every time from looking at your favorite websites my friend tells me, so go to the dustbin of history, microsoft. I'll be buying a few CD's by surface mail, and using the internet for text interchange and stock market charts. No financial videos, got that Vangard & Fideility?