I replaced your 2 tunes with small Fusion samples just to upload the file here. If you click on Data Elements and then change them out with your songs - it will automatically replace all the code bits and pieces with your songs.
On your level - everywhere that you had play a sample I replaced that with a global value.
Then on line 47 I inserted this:
* Hit Sound On = 1
+ Sound = 0
Special : Set Hit Sound On to 0
Sound : Play sample hit_sound
What this does is test to see if sound is on (i.e. sound =0) and if so, it will play the sample once and reset the value so that the sample is not played again, until there's another reason to play it.
If sound is off (i.e. sound = 1) then it won't play the sample.
Note also that there's a setting in the game properties - play samples over frames (under runtime options - sound options). If you tick this then when they progress from one level to another, the music continues playing seamlessly. If you don't tick that, the tune will restart on each level.
Please change the file name in the ini file to a sensible name that will be unique to your game. (the name "ThisGameSaveFile")