Disc Issue

So I was in me and my cousin's world, we work together on it and I usually surprise him with many different things. I was working on a project in our world when I wanted to play one of my favorite music disc's, Cat. I placed it inside the jukebox and it started playing, nothing out of the ordinary, that was until I tried taking it out and the disc was gone, almost like it erased itself. I tried destroying the jukebox to see if it would drop the disc but nothing happened, I even checked my inventory and it was gone. It took my a very long time to find that disc but at least I enjoyed my moments with it. I hope this description helps.