I confess that I had not previously heard of Toshiyuki Honda, but his music is distinctive and often wildly different for a film of this sort. Rather than out and out science fiction, there is a strong New Orleans jazz influence in many of the score's cues. The titular opening track is almost totally unexpected, sounding more suitable for mardi gras than sci-fi, but the unexpected tone is a delight and works brilliantly in the film itself. Three Faces of "Zone" sets up the more bluesy side which makes a nice connection between the darker areas of the city and the depression hit streets of 1930s America. However, the second half of the track features a gentle and more obviously filmic piano led theme for the female robot, Tima, which is an early highlight.
Perhaps the most daring scoring here is using jazz for some of the wittily staged chase sequences, rather than a symphony orchestra banging away for all its worth. Il Bombero is one such track not easily forgotton, with its queasy slurred woodwind and brass, backed by a manic drummer. Run is perhaps a little more straight laced, featuring the main theme more prominently, but the semi-minimalist jazz that uses a repeating background of percussion and brass hits, onto which is grafted variously quasi improvised solos, although not of the uncontrollably type so beloved by real jazz bands. Only the later Chase moves back to the orchestra for its momentum, but in truth, the larger ensemble is no more exciting, although Honda's writing here is every bit as accomplished.
The emphasis on the jazz element is not at the expense of the more "regular" passages which are much more of the sort expected for a film of this type. The music surrounding the Ziggarut has the kind of cyclic patterns that wouldn't be out of place in AI (to which the film bears a slight resemblance, yet predates Spielberg's far from perfect Kubrick homage) and the stirring Fury is as grand and dramatically powerful as anything by any Hollywood composer. As well as the previously mentioned finale of Three Faces of "Zone," Sympathy and Snow are superlative orchestral passages that add further dramatic weight to what becomes an innocent love story.
I would readily admit to having read reviews of varyingly obscure anime scores elsewhere and being highly skeptical of their quality based on the seemingly glowing praise. However, in this instance, I truly do think that Metropolis is a score worthy of discovery despite being by composer about which you may know nothing. Even if the thought of jazz doesn't appeal, there are enough orchestral cues to satisfy the volume junkies, but the jazz integrates surprisingly well even if it makes more sense having seen the film itself. For that matter, I highly recommend the film, which is a visual feast, moving deftly from epic social drama to something intimate and surprisingly poignant. If you can't find the CD in shops, do what I did and make your first online purchase from the iTunes store where it presumably can't go out of print.
Rating ~ 
Total Time ~ 59:07