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).
see: BWV29, BWV 120a, BWV 1006, BWV 1006a et.al.