This one is more like half-a-day. It's heavily inspired by some of the ambient music in Fallout New Vegas, and the general experience too. New Vegas's music is hit and miss; well, to be honest, it's more miss than hit, apart from the tracks that were taken from Fallout 1 (like the excellent 'Children of the Cathedral'). It's mostly made of grandiose, carefully arranged orchestral scores, which are at odds with the post-apocalyptic wasteland it should be trying to depict.
But every so often, for example in 'How The West Was Lost', it hints at country guitar, and that is where it shines. The quiet, sparse, calm desert settlements are embodied wonderfully by lazily timed simplistic pentatonics, the hint of tension under the surface captured perfectly by the careless bends and the buzzing open strings of a beaten up old steel string acoustic guitar and the endearing nonchalance of "you know what, I don't even care if this note is wrong".
That is the kind of vibe I was going for.
(Edit: sorry I have no idea why this isn't working on Internet Explorer. If you can't see the above audio controls then you need to be on Chrome or Firefox)