JANUS-FACED MP3 EP: Toward the end of April of this year, the Suicide in Installments netlabel posted its last (or, one hopes, simply its most recent) freely downloadable release, a six-track set by Mosca, titled Arcwelder. The EP alternates, quite consciously, between beatless exercises in background atmospherics (the angelic “Bolt,” the warped “Peeling Layers,” the nearly still “It’s Okay to Cry”) and tracks that put their beats front and center, only to often crinkle ’em in nifty ways (the gear-shifting “Bastard Generator,” the loopily funky “Preset,” the pleasingly rote “Mass”). Further evidence that Mosca knew exactly what he was up to in thus ordering the album, the set proceeds with sequentially longer tracks. So the first, a lush gauze, risks comprising its elegance by coming to a sudden close after barely a minute, and the last, a steady four and a half minutes built atop what sounds like someone rhythmically grounding a castanet into the floor with a boot, ekes out a zen state with its trance-inducing repetition. Arcwelder is available at the label’s website, suicideininstallments.com. And there’s more Mosca to be heard at retropublik.com.