Within the film the music exists almost as a character in itself as it forces itself into the narrative - never more so than when Richard Glover sings 'Baloo My Boy' directly into camera. Williams has created a score that feels alive. It has body and texture, it moves, it breathes and it surprises as it is utterly at home within the movie.
Outside the context of the film though it's possibly even better. A gigantic, roiling beast of a thing filled with tumultuous drones, grand sweeps, delicate melodies and gritty ambiences. For a soundtrack album to work outside of the movie is always a treat; for it to work this well is a rarity and a glorious achievement on the part of Williams and his compatriots.
I'm a huge fan of ambient / drone / experimental / whatever you want to call it music (it's what I do when I'm not here - www.quietworld.co.uk) and this is as fine an example as you will ever find and I wholeheartedly recommend it to you.
One complaint though. Why was this only ever released as a now almost impossible to find, and if you can find then impossible to afford, limited edition vinyl and as a download? The movie has been championed as being a 'multiple platform' release so why not the soundtrack?
Finally, I'm going to leave you with a little video about the making of the score.