Kind of like a jukebox surrounded by leather to make a jukebox in a bag kinda thing. right clicking it in your inventory opens a chest like gui where you can only store disks. right clicking on the disk allows you to play it on the go, and there are loop options and automatic switching, is this possible?
That mod just makes a slightly more useful jukebox block, as far as I know nobody has made a mod for a portable jukebox item to be held in the inventory, only ones that allow .mp3's to be played in the background.
The Jukebox pet from inventory pets is a portable jukebox, but is not a chest. Someone should add an inventory pets addon that surrounds the pet with 6 wooden planks, an iron nugget and a golden ingot in a crafting table to make a Jukebox chest pet.