The Nice (which, incredible as it seemed even at the time, was the warm-up act for P P Arnold the first time I saw it) did a stunning version of one of Bach's Brandenburg concertos. The track was called Brandenburger, the album was ARs Longa Vita Brevis, and Keith Emmerson was on keyboards.

T-tone, Whiter Shade of Pale was indeed consciously derived from the Air on a G String.