So I'm trying to explain to a friend of mine how Marty O'Donnell composed the music for Halo:CE, which basically boiled down to making it in "chunks". Each chunk was loopable with all the other chunks on a given track, and some chunks would be more intense versions of others, etc, and this allowed for a dynamic soundtrack that was subdued when the player was secluded, ramping up when enemies approached, and guitar-squealing when the shit hit the fan.

I recall a video or a podcast that had Marty himself explaining the process in his studio, and there was a segment where he played different chunks one after the other to compare them. I have been at a complete loss to find this video/cast anywhere. I'm 90% certain it was about Halo 1, specifically the chunks he used were the chunks and layers of Rock Anthem for Saving the World, one with just the drums, one ramping up with drums+strings, and one with the guitar kicking in.

Does anyone know what I'm talking about or have a link? I've been beating my head over this and googling everywhere and can't find anything like it. Any help would be appreciated.