DULUTH IS A CITY UNLIKE ANY OTHER. Okay, maybe that’s true of all cities, but it’s really true of this one. I’ve lived in a lot of different places, but nowhere else is as simultaneously intimate and various, worldly and homey, wild and civilized, as this one. And the most Duluth event of all, the one that best sums up the city and its music-obsessed citizens, is the annual, week-long Homegrown Music…