Alternate YouTube link: https://youtu.be/-kd1ouKAAVs
Quality on the video here is pretty fucking good. Took me a while to source it. If you don't get the joke, I'm sorry - it is kinda niche.
In hindsight, I realize that this honestly poor joke is gonna need explanation. And it will take spoilers.
SNW S01E02
The comet that looks to be destroying a world winds up using music as a language. The joke here is that a diminished ninth unless used with expertise sounds horrible