Hmm...I'm probably replying a bit too late, but
Propellerheads are Alex Gifford and Will White, two breakbeat/hip-hop/dance
(you can't really pigeon-hole them) people from the Roman's favourite party town of Bath.
David Arnold heard their magnificent futuristic spy-theme
"Spybreak" (found primarily on The Matrix soundtrack), and decided to give them a whirl with helping him contemporarise
OHMSS.
The full version of
OHMSS (not the radio edit), which is a hefty
9:52 in length, does indeed completely change pace halfway through, and Barry's
Space March, which
Leftfield remastered in the
Shaken And Stirred album, can be heard building up to a climax, before changing back into a funked up version of
OHMSS in a different key.
I am a major Props fan, and I have been disappointed with their 'quietness' of late (after Will White had an operation late '98, no singles have been released since featuring 'Propellerheads' as a group), but supposedly they are releasing a second album in March, which is excellent news after their ASTOUNDING debut album
"Decksandrumsandrockandroll" which was released in early '98.
Only Gifford collaborated with Arnold on the amazing action cue
"Backseat Driver" heard in Tomorrow Never Dies, but the version in the film is markedly different to the version heard in the soundtrack, the ending features the 'James Bond fanfare' for instance.
Any other questions? Just ask.

Cheers,
Paul