Nirvana is often thought of as sloppy, slacker, etc. but they took their music very seriously. When getting ready to record Nevermind, Kurt Cobain had the band

Nirvana is often thought of as sloppy, slacker, etc. but they took their music very seriously. When getting ready to record Nevermind, Kurt Cobain had the band rent a rehearsal space in LA for 3 months and practice every day - it was a full time job. Kurt in particular played, recorded, and wrote nearly every day for years so although he was a creative genius he also put in the work finding the sound and style he wanted to perfect. And he did. There’s a lot of nice stories about in the year leading up to the release and this is just before he got into heroin. Pretty much after the release he started using heavily and all his hard work was given over to it.