for example, there is no such thing as speedbass.
If some of the music was just written for inclusion in the guide (which is entirely possible from my point of view since I can identify many, but not all of the examples), how would it be less real than anything else at the bounds of near-infinite obscurity? It would just be another "artist" backed by the same person or collective as the Ishkur handle, just like the numerous incarnations of Bangalter.
The instaplay samples from somewhere in the middle of a representative song are what makes this work so well, I think.
It's striking how different it feels compared to MusicMap from the sibling post (which is also neat): MusicMap plays the entire song from the start, so it takes a while for each song to get going. The YouTube embed also takes a second or two to initialise.
Every Noise at Once, on the other hand, gives you a fairly good idea what a genre or artist is a about the moment you click the link. Very similar to Ishkur's Guide in that regard!
The display of relations between genres is pretty much unparalleled, including the dive into subgenres solely focused on obscure features of parent genres, such as the kinkery going on in trance.