Gowanus, a Brooklyn neighborhood so unlovely it’s been named an EPA superfund site, is Ground Zero now for music lofts, as reported in my new City Arts-New York column. In a half dozen or so artist-run spaces — including IBeam, Douglas Street Collective, Littlefield, the Brooklyn Lyceum and Issue Project Room — available for presentation and rehearsal of hard-core experimental sounds, dance, video and performance art, the programming is typically spiky, ambitious and unsentimental.