Seven weeks. That’s just 49 days, and an insignificant length of time in the grand scheme of things. But 30 years ago, over seven weeks during the summer of 1991, one hell of a lot happened in the world of rock. The passage of time has meant that often people think back to 1991 as the summer of grunge, but in truth it really wasn’t. It might have been a period in which many pivotal albums that would herald the heyday of grunge were released, but much of their success would come later the following year or even long after that.