Artists/bands who completely changed pop music?

What artists do you think completely changed pop music all on their own accord over the course of history?  These are the biggest of the big.  Not people who merely had influence or who were legends, but people/bands whom impacted everyone who came after them.

Duke Ellington - Ushered in the big band era of the 1930s and early 1940s.

Frank Sinatra - Responsible for the shift of pop music to targeting teenagers instead of adults.  Most people today don't know this, but Frank Sinatra was one of the first teen sensations in music.

Elvis Presley - Ushered in the Rock n' Roll era

The Beatles - The Sixties wouldn't have happened like they did without them

Michael Jackson - he set the template for modern pop music

Madonna - Changed the game for female performers and what was acceptable

Eminem - Without him, hip-hop wouldn't have had the widespread popularity it has had with white audiences.  People forget that in the '90s, hip-hop was more segregated as a genre than it was in the 2000s and afterwards

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I debated on adding Nirvana but I'm not sure if they were quite that impactful, though they did kill hair metal.