Pigstep music disc does not generate in bastion remnants' loot chests. I've checked over a hundred bastion loot chests and none of them containded the Pigstep music disc. I may have been extremely unlucky but this issue is definitely worth checking. On the other hand if I finally managed to find the disc, I wouldn't be able to listen it in a jukebox, because it is still broken, even though the last updates' changelog said that this issue has been fixed BUT IT HAS NOT.