Back in August, we previewed several selections from the upcoming Roots of Chicha 2 album, the second compilation of the unique psychedelic strain of cumbia that first sprung up in Peru during the late ’60s and early ’70s. The record is set to hit shelves next week, so the Barbès camp has liberated one of the songs for download, the trippy “Agua” from Manzanita y su Conjunto. At times more like a jam session than a proper song, “Agua” features tribal percussion, wonky guitar solos, some organ flourishes, and some pretty “out there” vocal refrains. Why can’t modern cumbieros make music this druggy?