a few things:

- what essential means to me is different from what it means to you, so don't waste energy thinking about why I might have picked less popular tracks over some others

- tracks are not necessarily chosen by tag; artists mis-tag their tracks all of the time

- each playlist is capped at 15 tracks, not looking for additions or replacements unless the case for the track is very strong

- I created environments that intentionally show the best and the most diverse musical qualities of each genre

- I tried to pick the most diverse cast of artists for each genre that I could, but because several genres are dominated by two or even one person in some cases, repeat artists were inevitable