[OrigamiSensei]

Although I consider Nirvana and Cobain not to be overrated I have to simply laugh at the notion that they invented "alternative rock" or for that matter even the Seattle/Pacific Northwest grunge sound. It seems to me that alternative rock was an outgrowth of the new wave movement, with groups like REM, the Smiths, XTC, and more obscure groups like Aztec Camera carrying the flag. I'd say alt-rock was pretty well established as a genre by 1984, seeing as I lived through that era and listened to a lot of it.

The Seattle grunge sound had already been established by 1986 or 1987 as I clearly remember watching grunge pioneers Green River opening at a club for Jane's Addiction in late '86 or early '87. If I recall correctly Green River spawned Pearl Jam and one or two other well-known grunge groups. I thought they were crap, but that's a different story. They probably weren't even the first but they were early in the movement and they did have a lot of buzz.

I think it's fair to say that the pop sensibility Cobain and company brought to the grunge sound helped to put it over the top in terms of popularity but to claim they invented whole genres is pretty far-fetched.