Thanks to Virus for testing out the file...found out it's a conflict between some of the codes that i was using.. no solution yet....but i was able to load and change music without crashing the game under the normal mode (no cheat code) apply. then exit and go back to the modify mode(with code). and your music will still able to play but just don't open your stereo or music player while under the modify mode or the game will crashed (just like from before).

just thought if anyone else is having this problem.. this is the solution so far..