Mapping from disk filenames to track titles (they can be seen in the sound-chooser menu in the game) was a pain for me. You basically have to listen to them all and correllate them yourself, AFAIK. Luckily, there are some patterns, though it is messed up in some places. So I'll document it here.
The ones labeled RH came from the Rush Hour music CD titles (see refs for downloads). The SC ones are the original game's music, which I got titles from using the in-game menu.
/- Disk File name | /- SC4 or Rush Hour expansion? | | /- track number in the CD (for now, RH only) | | | /- name Region/Music/SC4ep1_02_G.mp3 RH 01 Bombay ALSO Area 52 in the game menu Region/Music/SC4ep1_03_G.mp3 RH 10 Dig Deep Region/Music/SC4ep1_08_G.mp3 RH 09 Arctica Region/Music/SC4g1.mp3 SC Above The Clouds Region/Music/SC4g2.mp3 SC Shape Shifter Region/Music/SC4g3.mp3 SC Terrain Region/Music/SC4g4.mp3 SC Without Form Region/Music/SC4g5.mp3 SC Taking Shape Region/Music/SC4g6.mp3 SC Primordial Dream Region/Music/SC4g7.mp3 SC Parallel View Mayor/Music/SC4ep1_01_M.mp3 RH 02 Bumper to Bumper Mayor/Music/SC4ep1_04_M.mp3 RH 08 The Morning Commute Mayor/Music/SC4ep1_05_M.mp3 RH 04 Wheels of Progress Mayor/Music/SC4ep1_06_M.mp3 RH 06 Deserted Mayor/Music/SC4ep1_07_M.mp3 RH 05 Metropolis Mayor/Music/SC4ep1_09_M.mp3 RH 11 ElectiCITY Mayor/Music/SC4ep1_10_M.mp3 RH 03 Floating Population Mayor/Music/SC4ep1_11_M.mp3 RH 07 Chain Reaction Mayor/Music/SC4m01.mp3 SC Rush Hour Mayor/Music/SC4m02.mp3 SC By The Bay Mayor/Music/SC4m03.mp3 SC The New Hood Mayor/Music/SC4m04.mp3 SC No Gridlock Mayor/Music/SC4m05.mp3 SC Re Development Mayor/Music/SC4m06.mp3 SC Bohemian Street Jam Mayor/Music/SC4m07.mp3 SC Urban Underground Mayor/Music/SC4m08.mp3 SC Street Sweeper Mayor/Music/SC4m09.mp3 SC Crosswalk Talk Mayor/Music/SC4m10.mp3 SC Tarmack Mayor/Music/SC4m11.mp3 SC Night Owl Mayor/Music/SC4m12.mp3 SC EpiCenter Mayor/Music/SC4m13.mp3 SC Gritty City Mayor/Music/SC4m14.mp3 SC Zone System Mayor/Music/SC4m15.mp3 SC Transit Angst Mayor/Music/SC4m16.mp3 SC Landfill Mayor/Music/SC4m17.mp3 SC Oasis
http://simcity.ea.com/coolstuff/rh_music/index.php Rush Hour music CD and downloads.
http://www.geocities.com/programmerblank/Current_FTP_List.txt Someone's music track list.