Downy Mildew were perhaps the archetypal SNAP Band: scrappy, independent, locally beloved but nationally obscure, and possessing an earnest but ambitious indie-pop sensibility. The LA band’s December 1990 session was their third for Deirdre, and it arrived at a transitional time. They were between record labels, having parted ways with Santa Monica’s Texas Hotel Records. And their next album, 1992’s “An Oncoming Train,” was still two years away. But Downy Mildew are here in fine form, offering up punchy and artful renditions of material from throughout their career.