Think I got it working. Titles are appearing, and it's the right song names. No idea what I did to make it work but at least it works

Added that into the main.lua file in place of what was there before and it still won't show the names. Either some mod is conflicting somehow, or isaac is being isaac

the jukebox mod came out after a lot of music mods had already been made, the person who made it added track lists for those soundtracks to the jukebox manually when they released it in order to support those older mods
if you check my later soundtrack mods (Hades onwards) you'll see the same function in the main.lua

as for the names still not showing up I don't know, it worked for me after I added that code into the main.lua, did you add it in the right place? here's what the whole function should look like

function mymod:startGame()
if SoundtrackSongList then
AddSoundtrackToMenu("Muse")
if Titles then
AddTitlesToJukebox("Muse", "Muse", "Muse", Musetracklst)
end
else
Isaac.ConsoleOutput("The Soundtrack Menu Mod is required for Muse Soundtrack")
end
end
mymod:AddCallback(ModCallbacks.MC_POST_GAME_STARTED, mymod.startGame);

but that does not appear in the main.lua of the other music mods that I looked at, added that code and it still won't show the names

the song names aren't appearing because you didn't include the line of code that actually adds the track names from your mod to the list, need to update like this (and yes the 3 'Muse's are intentional)

AddSoundtrackToMenu("Muse")
if Titles then
AddTitlesToJukebox("Muse", "Muse", "Muse", Musetracklst)
end