Proficient instrumental virtuosity can ruin a rock band. When a group's members get too good on their instruments, it can lead to grandiose pomposity or, even worse, jam-band wankery. Riddle of Steel falls into none of these traps, though its three members could claim the bass, guitar and drum thrones of St. Louis. Instead of showing off, they play intricately, brutally and often beautifully in the service of propulsive progressive-rock songs tempered with punk's attitude and metal's edge. Riddle of Steel sounds like how it might have been if Frank Zappa had fronted a punk band: experimental, with the right amount of accessibility and humor. Live, they amp up their tunes into a furious froth that makes even the hippest of hipsters move and the most dedicated of punks air-guitar along. Riddle of Steel has saved progressive rock in St. Louis. Next, the world.