Agreed. The first time I really paid attention to it was when I visited nipton for the first time and bumped into the legion. When the vulpas guy was describing the lottery the music sounded very appropriate like I was witnessing something terrible and inhumane. It really svcked me into the whole mood and atmosphere of the situation.
This track is from Fallout 2, and it did fit the mood perfectly. Whoever designed the music for F1 and F2 was a genius at establishing atmosphere.
There is one track from fallout 1 that still unnerves me every time I hear it. I'm at work right now, so I can't look up the name, but it sounds like some type of machinery clacking away in the background and every few seconds there is the sound of bells which get increasingly louder. I remember the first time I heard it in fallout 1 during a random encounter and then again at the church near the end of the game. It is
incredibly menacing.
If you go into the music sub-folder in your fallout install folder you should be able to find it under the old tracks.
That was one of my complaints with fallout 3, was that the ambient music just wasn't as powerfull as the original fallouts. One of the best things they did with NV was bringing back the original tracks.