While they existed in some form or another before, Rap and Hip-Hop really brought the “diss track” into the mainstream. Most notable were the rap feuds between the East Coast and West Coast rappers during the 1990s… (Did it ever get more vicious than 2Pac’s “Hit ‘Em Up?”)
However, there are plenty of other great examples in pretty much every other genre of music, both before and after the heyday of the Hip-Hop diss track… maybe not as direct as “you claim to be a playa but I fucked your wife”, but one could make a good argument that the more polite-sounding songs that eviscerate their targets are even more devious and cutting due to their subtlety.
One of my favorite examples is the song “Coattails of a Dead Man” by Primus (guest-starring Tom Waits), written about Courtney Love without any direct mention of her name:
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