Hi! I finaly found out how to create Race specific Music. I couldnt find any solution here in the Forum, so decided to find a way by my self. Every race can have thier own Music style now. Means they dont share any Music. Some Quiet and Battle Music a shared between the Races, my mod remove this.
If you´re to lazy or if it wont work for you, you can DL a Entrenchment Mod here. Just read the MusicMod.txt inside the Archive:
New Version with Vasari support!
http://files.filefront.com/MusicModzip/;13844374;/fileinfo.html
Feedback and suggestions are welcome! 
Tutorial:
Step 1: Create a Folder (e.g. MusicMod) in the Sins Mod dir.
Step 2: Create a GameInfo Folder in your Mod (MusicMod) dir.
Step 3: Go to your SINS/GameInfo Directory and copy following Files and paste them in to your MusicMod/GameInfo/ dir:
Game.musicdata
SoundMusic.sounddata
Step 4: Decompile PlayerPhase.entity, PlayerPsi.entity and PlayerTech.entity into TXT with ConvertData(_Entrenchment).exe
Step 5: Add your Music Info into SoundMusic.sounddata e.g.:
music
name "MUSIC_BATTLE_1"
fileName "Advent Fight 1.ogg"
isLooping FALSE
actionLevel 0.6
actionRange 0.4
emotionLevel 0.0
emotionRange 1.0
name "MUSIC_BATTLE_2"
fileName "Advent Fight 2.ogg"
...
name "MUSIC_BATTLE_5"
In this case, I´ve edited the existing "MUSIC_BATTLE_1" entry. You´ll notice that I´ve edited a existing entry, just changed the filename to avoid any possible problems.
Step 6: Now edit every Music entry that shouldnt play random or hardcoded Race specific Music and replace following lines with:
actionLevel 0.0
actionRange 0.0
emotionLevel 0.0
emotionRange 0.0
Step 7:
- Open PlayerPsi.entity (because we used Advent Fight 1.ogg in the lines above)
- Go to the line "musicThemeData"
- Remove every "musicTheme" entry under the first two "musicThemeCount" lines.
- Add your own lines from SoundMusic.sounddata e.g.:
musicThemeData
musicThemeCount 10
musicTheme "MUSIC_QUIET_1"
musicTheme "MUSIC_QUIET_2"
musicTheme "MUSIC_QUIET_4"
musicTheme "MUSIC_QUIET_5"
musicTheme "MUSIC_QUIET_6"
musicTheme "MUSIC_BATTLE_1"
musicTheme "MUSIC_BATTLE_2"
musicTheme "MUSIC_BATTLE_3"
musicTheme "MUSIC_BATTLE_4"
musicTheme "MUSIC_BATTLE_5"
scareThemeCount 5
musicTheme "MUSIC_BATTLE_1"
musicTheme "MUSIC_BATTLE_2"
musicTheme "MUSIC_BATTLE_3"
musicTheme "MUSIC_BATTLE_4"
musicTheme "MUSIC_BATTLE_5"
announcementCount 1
musicTheme "MUSIC_ADVENT_ANNOUNCEMENT" (afaik this line is unused, but i left it untouched to avoid problems)
(musicTheme "MUSIC_QUIET_1,2,4,5,6" and musicTheme "MUSIC_BATTLE_1,2,3,4,5" have Advent specifc Music)
Step 8: Open Game.musicdata and remove any Race specific entrys you edited in SoundMusic.sounddata.
TXT
musicThemeCount 24
musicTheme "MUSIC_QUIET_7"
musicTheme "MUSIC_QUIET_8"
musicTheme "MUSIC_QUIET_9"
musicTheme "MUSIC_QUIET_10"
musicTheme "MUSIC_QUIET_11"
musicTheme "MUSIC_QUIET_12"
musicTheme "MUSIC_UPBEAT_1"
musicTheme "MUSIC_UPBEAT_2"
musicTheme "MUSIC_UPBEAT_3"
musicTheme "MUSIC_TROUBLE_1"
musicTheme "MUSIC_TROUBLE_2"
musicTheme "MUSIC_TROUBLE_5"
musicTheme "MUSIC_TROUBLE_6"
musicTheme "MUSIC_TROUBLE_7"
musicTheme "MUSIC_TROUBLE_8"
musicTheme "MUSIC_TROUBLE_9"
musicTheme "MUSIC_BATTLE_8"
musicTheme "MUSIC_BATTLE_9"
musicTheme "MUSIC_BATTLE_10"
musicTheme "MUSIC_BATTLE_11"
musicTheme "MUSIC_BATTLE_12"
musicTheme "MUSIC_BATTLE_14"
musicTheme "MUSIC_SAD_1"
musicTheme "MUSIC_SAD_2"
musicTheme "MUSIC_SAD_3"
(As you can see I removed "MUSIC_QUIET_1,2,4,5,6" and "MUSIC_BATTLE_1,2,3,4,5".)
Step 9: Start the Game. Activate the Mod. Play the Game.