FIVE YEARS AGO, punk came in only three shades of cool: hardcore, screamo, and math rock (or some sexless composite of these). The '90s weren't "in" yet, an emo dance party at Holocene would have seemed surreal, and crusty arbiters of taste reflexively dismissed anything sounding even vaguely blues-derived as hokey. (I'll never forget putting Elliott Smith's Figure 8 on in Laughing Horse Books and hearing someone describe it as "dad rock"). 

Writing about musical history this recent feels sort of ridiculous, but the reemergence of mid-tempo, melodic guitar rock in the underground can almost certainly be traced back to bands like Joyce Manor and the Sidekicks—reformed pop-punk groups with a contagious revisionist love for Weezer's least-shitty album. Philadelphia's Sheer Mag's influences stretch back an extra generation—they're a punk band that doesn't make overtly punk music. 

There are a couple of reasons why Sheer Mag is currently one of America's most compelling bands: They shamelessly pillage a period in the rock 'n' roll canon still unexplored and considered relatively uncool by most young punks—swaggering and quirkily melodic classic-rock bands like Slade, Thin Lizzy, and early Queen—and shun the press and conventional forms of internet promotion, enshrouding the group in an irresistibly elusive mystique (they have a "fan-run" Facebook page with more than 7,000 likes). Needless to say, they would not speak to the Mercury.

Sheer Mag's latest release, III—the third in a triumvirate of spotless 7-inch EPs—almost sounds like a Big Star-esque artifact from a bygone era. Opener "Can't Stop Fighting" is a sleazy, sauntering argument in favor of the dominant seventh chord, and "Nobody's Baby" is one of the catchiest guitar-based songs a band's released in years, an anthemic power-pop chef-d'oeuvre on par with anything released by the Raspberries or Dwight Twilley. But despite the loud-and-proud '70s rock reverence, Sheer Mag's members are far from mere revivalists—the group's aesthetic and spirit is resoundingly punk, even if their music is anything but.Â