Both the original by Procol Harum and cover by Annie Lennox are from a manic phase of the 15-year cultural excitement cycle (1967 and 1995). Both are slow songs, showing that "manic" does not mean constantly bouncing around in a frenzy, but sometimes feeling carefree and almost invincible -- as opposed to the refractory period feeling of the vulnerable phase, or the return to normal energy levels during the warm-up phase.
This pair also fits into a pattern that I've discussed before, one with very few examples. That is, a mellower cover of an intense original -- but using more synthetic instrumentation than the original, rather than more acoustic. The usual move is to switch from electronic to acoustic in order to reinforce the mellower interpretation (e.g., the "Unplugged" era of the 1990s).
Here, the original is not fully acoustic, but it does have a piano, and sounds more naturalistic at any rate compared to the distinctly more synth-y and danceable cover version. You'd think the synthetic timbre and danceability would be reinforcing a higher-energy interpretation of the original, but it's much more mellow -- a pleasing surprise.