According to Op:
To my knowledge this was coded by JankesPro12.

This module randomizes the music only for your ScreenPack (NOT FOR STAGES/BATTLE)

Here's a reference list:

bgmlisttitle ={"sound/title.mp3", "sound/After Cooking - Brainstorm.mp3"}
bgmlistoption ={"sound/options.mp3"}
bgmlistselect ={"sound/select.mp3"}
bgmlistvs ={"sound/versus.mp3"}
bgmlistreplay ={"sound/replay.mp3"}
bgmlistcontinue ={"sound/continue.mp3"}
bgmlistresults ={"sound/results.mp3"}
bgmlisthiscore ={"sound/hiscore.mp3"}
function f_changeBGM()
motif.music.title_bgm = bgmlisttitle[math.random(#bgmlisttitle)]
motif.music.option_bgm = bgmlistoption[math.random(#bgmlistoption)]
motif.music.select_bgm = bgmlistselect[math.random(#bgmlistselect)]
motif.music.vs_bgm = bgmlistvs[math.random(#bgmlistvs)]
motif.music.continue_bgm = bgmlistcontinue[math.random(#bgmlistcontinue)]
motif.music.results_bgm = bgmlistresults[math.random(#bgmlistresults)]
motif.music.hiscore_bgm = bgmlisthiscore[math.random(#bgmlisthiscore)]
motif.music.replay_bgm = bgmlistreplay[math.random(#bgmlistreplay)]
end

hook.add("main.t_itemname", "changeMySongDamnIt", f_changeBGM)


How to install:
Download and then place the file inside your External/Mods folder

How to use: EXAMPLES HERE
This is for the titlescreen--->>> : bgmlisttitle ={"sound/title.mp3", "sound/After Cooking - Brainstorm.mp3"}
This is for optionscreen--->>> : bgmlistoption ={"sound/options.mp3", "sound/name your song here.mp3"}