This parallel recording compares the very dry, precise studio sound (here in the acoustics of the Teldex studio and the sound of a New York Steinway from the 1950s), with a sound that one might expect in a modern concert hall (here the acoustics of the Berlin Philharmony and a current German Steinway D).
The score of the earlier "Piece" contains a second version of some bars. A third, significantly expanded version was created around 1891 under the title Fugue.