In the early 2000s, rock was struggling to deal with the decline of grunge. This eventually lead to post-grunge and the temporary "death" of rock, at least in the mainstream.
However, in the late 90s and especially the early 2000s, "garage rock" acts like The White Stripes, Electric Six, The Dirtbombs, and Kid Rock broke out of the Detroit scene and got some recognition, although most of it over in the UK.
What if Detroit's new alternative scene (influenced by electronic, dance, and rap music in many cases) became the new grunge? What would this mean for the underground music of the 2000s, the emo rock scene in the late 2000s, and the indie rock revival of the 2010s? How would it effect other genres? How long could the "Detroit Sound" conceivably last?