The Music code is not hard, you just add songs into the category "campaign", "battle", "title". Then you can have multiple songs for different situations.
"music":{
"music_title":[
{"file":"title1.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3},
{"file":"title2.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3},
{"file":"title3.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3}
],
"music_campaign":[
{"file":"campaign1.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3},
{"file":"campaign2.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3},
{"file":"campaign3.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3},
{"file":"campaign4.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.3}
],
"music_combat":[
{"file":"combat1.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.01},
{"file":"combat2.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.01},
{"file":"combat3.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.01},
{"file":"combat4.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.01},
{"file":"combat5.ogg","source":"sounds/BFG/music","pitch":1,"volume":0.01}
],
},