[La Mano Gaucha]

The "Mars" you're talking about is by KC and the Sunshine Band. Just kidding... King Crimson. In fact, this is not really a version of Holst's "Mars" per se. In reality, the rendering by KC ("The Devil's Triangle" or "Mars", depending on what version you would be listening to) is an extended (and rather monotonous) fantasy upon the principal melodic theme and principal 5/4 rhythmic signature of the original piece. There is little development in the KC version, and the group was not aiming at truly transcribing the actual piece. The KC version is in essence an extended, monolithic crescendo, rather than a clearly defined ABA' form with introduction and coda. Like I said above, it's only a fantasy on some thematic elements from the original. As a side note, notice that the tempo is also radically slowed down in the KC. The harmonies and progressions are also quite different. It's effective, to a certain degree, but not at all a true "version" of the original. (However, sometimes KC did employ the original coda, more or less.)

The same could apply to ELP in their classical manner, but to a lesser degree -- this band tended to stick closer to the originals, sometimes blatantly, sometimes very subtly. An unusual, interesting (but quite underrated) track by ELP is "Abaddon's Bolero", from "Trilogy". The structural and gestural idea of this track derives directly and consciously from Ravel's "Bolero", but the band didn't use a single quotation from the Ravel, whether melodic, harmonic or rhythmic. In this particular instance, the band has fully assimilated a warhorse and created a new work, rather than a pastiche. That's why I have always admired this ELP track, even if it's not one of their best.

LMG