Music discs made by C418, and Pigstep, don't play when the Jukebox/Note Blocks setting is at 0. Which, makes sense. But discs other than that, strangely do play.

Steps to reproduce:

1. Set the Jukebox/Note Blocks setting all the way down to 0.

2. Play either one of the aforementioned music discs in a jukebox.

Expected results:

The music discs do not play.

Observed results:

The music discs do play.