#931: The nothingness of a black hole generates a sound in the key of B flat.
Verdict: False (sort of)
Black holes are crazy. For those who aren't quite sure what they are, here's a little primer for you. There are many variations and sizes and origins for black holes but the incredibly untechnical tl;dr version is this: It's a point in space that is so dense and compressed (TONS of mass squeezed into a very tiny space) with an absurd amount of gravity that even light can't escape. You literally can't look at one, you can only see what it's doing to the objects around it, as well as its effects on space and time. They are often the result of massive, dying stars, though again there are variations and this is an over-simplification.
So now for the "False (sort of)" rating. It's actually pretty simple: There is a blackhole that "emits" a tone of B-flat, but not all blackholes do this and NASA even has examples of other notes. The black hole Snapple is probably referring to is a Super Massive Black Hole" in the Perseus Cluster. This note is also 57 octaves lower than middle-C, making it, "the deepest note ever detected from an object in the Universe" (as of 2003). It is literally over a "million billion" times lower than what the human ear can hear. Perhaps South Park was on to something...
So let's hit another aspect of black holes since that was all pretty simple and since black holes are so totally crazy awesome while simultaneously operating as a potential source of literal and existential dread that you can't control!
If you observe an object entering a black hole, it will first seem to "slow down" then appear to freeze in motion and time because the light can't escape, meaning it'll take an infinite time to reach you. You are quite literally stuck with the "last image" of the object before it crosses what is called "The Event Horizon," the point of "no return" for objects near a black hole. The closer you get to this point, the more time seems to "slow down." If you saw the movie Interstellar you saw this effect at work on the water planet. The planet was pretty close to a black hole, meaning it felt some of the effects (while remaining outside the event horizon). The longer they spent on that planet, the more time passed outside of the area due to the relative effects of time. A few hours on the planet equaled dozens of years in "normal" space.
So yeah, don't get too close to your local black hole, everyone.