creating a thread to get some more opinions and discussion on these genre tickets:
from the brief research I’ve done, these look like two distinct (but probably closely related) subcultures. with MADs apparently being older, starting in the mid-80’s, I think YTPMV should be a subgenre of MAD, or both genres as subgenres of Experimental or maybe EDM?
tagging @Victini, as they brought up MADs on the original ticket
You definitely did more research on MADs than I did - didn’t know they were rooted in the mid-80s. I do know that the (modern/Niconico) MAD community does have some crossover with YTPMV, to the point where this was a point of contention when people on Rate Your Music were trying to get it through there. A “YTPMV / MAD” combined genre was proposed due to the crossover and similarity, but was shot down as the two cultures were vastly different even with the crossover, and they didn’t want another “Baggy / Madchester” situation where a genre had two names. I’d imagine if they’d known about MAD’s roots that would’ve been shot down more.
The parent of YTPMV has also been a point of contention on Rate Your Music, as well. It seems that within the limits of RYM, Plunderphonics would be the best parent genre for YTPMV. However, there was some pushback from people who disagreed with YTPMV being considered an Experimental sub-genre, in which Plunderphonics is part of.
I remember when I was checking out the YTPMV submissions on RYM, I agreed on YTPMV being a specific type of plunderphonics. I guess the debate here is whether people here agree with YTPMV and MADs being experimental enough to be a plunderphonics subgenre. If there’s a relationship attribute where genres can be classed as related (dunno yet, the genre updates have been quite recent), YTPMV and MADs can definitely be linked that way.
honestly, the extent of my research on MADs is the Know Your Meme article on the subject 
both being a subgenre of Plunderphonics would be another solution
We have Plunderphonics as a subgenre of Experimental too, because it doesn’t fit anywhere else, but I see no problem with these collages being under experimental anyway. That said, “mad” as a genre tag seems a bit confusing - since it’s also a common word and our tags are all lowercase. We don’t have a lot of uses though so maybe it’d be ok to just downvote those few that don’t apply…
Added these - hopefully “mad” won’t be a problem once we have moods, but if it is, we can rename it. It just felt off to call it “mad music” or “mad video”.
MAD are sometimes referred to as “Music Anime Douga” although other sources claim it’s “not an acronym for anything”:
Also, does this mean “same music with a different video” are now “allowed”?
I don’t think that’s ever been specifically not-allowed, although I can see how that might be kinda problematic if people expect to only find official videos / cannot distinguish official videos from the rest. If this becomes big enough to be a problem then we’ll need to find a solution, even if just an {unofficial} attribute 