Acidic plays the sort of dense, noisy rock that’s not quite metal, not quite punk. But with its pulsing rhythms, not-too-serious lyrics and towering guitar solos, it’s the kind of rock that begs to be heard. The Los Angeles-based foursome has been working hard toward notoriety since its inception in 2008. Last year was Acidic’s biggest step forward yet, touring nonstop, dropping its most promising album and releasing a music video for the single “Copper Man” so ridiculous, nearly a million people have viewed it on YouTube. Now rolling through the upper left side of the country for what they’re dubbing the Electric Cool Aid Tour, the four-piece lands at the Knitting Factory on Saturday.