My primary source of music discussion at the moment is the 4chan subforum known as /mu/. The community is incredibly diverse, ranging in interests from classical, to hip-hop, to pop. They also have dozens of running inside jokes, and the most typical of these jokes revolve around a category of music they refer to as…
mu/ Essentials
Bloomsbury 33 1/3 book competition
Trance Melodies & Sounds Vol.1-3 Bundle – essential audio media
Essential Charts, 4chanmusic Wiki
Wes Montgomery/Cannonball Adderley Cannonball Adderley & the Poll Winners [ Essential Jazz Classics] CD
Every /mu/ essential album and my opinions on them - Rate Your Music
Sad Sixths Levels 1-3
OSO volume 20 issue 2 Cover and Back matter, Organised Sound
Pianote
Essential Music Theory Book - 57 matching results
Billy Joel The Essential Video Collection New DVD (Regions 1, 3, 4, 5 & 6)
Roblox Music Videos T-Shirts for Sale
Holy Forever Bethel Music
For the hell of it, made Topsters for all the section of the /mu/ Essentials chart : r/Topster