Earlier today one of the composers for The Simpsons: Hit & Run, Jeff Tymoschuk, put the original demo tracks for all the songs he composed onto his Soundcloud page.
Audio (Click to Open)
Compared to the music in the final game, these are much less compressed (44100Hz vs 24000Hz) and feature different instrumentation, differing quite drastically in some cases. This mod adds these versions to the final game!
The tracks have all been edited so they loop fairly well (about as well as they did in the vanilla game). In the case of Professor Frink's theme, I had to splice in the regular SHAR version at the end as the demo track is missing that part of the song, which is a bit annoying but there's not much I could do about it. The audio itself is stored in 160kb/s OGG files (which is the default export setting in Audacity) however I may make a FLAC version as well for all the audiophiles out there.
The mod is also decompilable, so if you want to use these tracks in your own mods you can!
At the moment there are only these three songs (since these are the only three Jeff Tymoschuk composed) but if others are found at some point in the future, I will add them as well.