Documenting all instances of post-rock up until Slint's 1991 release "Spiderland"

For an album to be considered as "must hear" it must be of some historical significance, whether that be musically, politically, or otherwise. This is not an endorsement of what I find to ...

Documenting all instances of trip-hop & down-tempo until DJ Shadow's 1993 release "In / Flux"

Documenting all instances of shoegaze and dream-pop until My Bloody Valentines 1991 release "Loveless"

Documenting all instances of hip-hop up until Run-DMC 1984's eponymous release "Run-DMC"

Documenting all instances of electronic music up until Kraftwerks 1977 release "Trans Europa Express", icluding turntable music, tape music, sound-collage, moogsploitation, glitch, ambient, ...