San Antonio’s Whirlybirds are the bubbling liquid of garage pop filtered through the snotty mesh of punk — masters of a tin and rev sound occasionally reminiscent of some of the Rolling Stones’ dirtier blues-rock. This KRTU Plugged In session — the first recorded document of the group’s relatively short existence — treats listeners to six originals and one raucously pretty Who cover (“I Can’t Explain”). The quartet’s sound is natural, confidently situated between inspirations old and new, catchy in a delightfully lingering kind of way.