What do you call music that has been lumped together, but isn’t unified by similar rhythms, instrumentation, subject matter, or geographic origin? Back in the eighties to early-nineties, we called it college rock. It had no major defining characteristic, other than the obvious: if a song or artist was played almost exclusively on college stations, then it was college rock. For a while, that bond was more than enough!
The rise of grunge music from the Seattle scene to the rest of the country was sudden and unexpected. Nirvana led the way, but they were neither the first, nor the last grunge band that the city helped produce. The grunge era proved short-lived, but for a time it was very potent.