I chose to compare the first variation of Gould’s 1955 and 1981 recordings of the Goldberg Variations. (1955 — 0:00-1:55 / 1981 — 0:07-2:58)
In his 1955 recording, Gould has a significantly faster tempo, and his style of playing is snappy and his tone is bright in comparison to his later recording. His ornaments are faster and he doesn’t do much stretching of the tempo or rubato. In contrast, his 1981 recording is much slower and more mellow. He uses a lot more rubato, and he spends much more time on his ornaments. He really uses dynamics to create a intimate and heartfelt sound, playing much quieter at some parts than he did in his other recording. He sits for longer on his dissonances and enjoys where the music goes, taking more time to draw attention to different directions that the music is leading to.