Minecraft wiki entry for Obtaining_every_music_disc, associated text: 1 Why bother?
2 Skeletons and creepers
3 Chest loot in structures
3.1 13 and Cat
3.1.1 How to obtain
3.2 Mellohi and Wait‌[BE only]
3.2.1 How to obtain
3.3 Pigstep
3.3.1 How to obtain
3.4 Otherside
3.4.1 How to obtain