I had an old public domain copy of the movie "Metropolis" with random classical music stuck on it. I wiped all that and tried scoring it with rock music. Lots of (mostly German) heavy metal, some odds and ends. For the scene where Freder declares his love for Maria after hearing her speak in the catacombs, I used this song and it was perfect.
I think it was great that Bungie placed her music in Halo 3: ODST. Really reflects on the sad stories of the ODST team. I remember this song playing when walking through New Mombasa: deserted, lonely.