Twenty years ago, Elvis Costello wanted to bite the hand that fed him; on Superdrag’s second major-label album, frontman John Davis bares his teeth. A former Buzz Bin baby, the band makes its latest ring hardest and truest on “Do the Vampire,” a Wholike yelp against backlash from hometown fans and radio, and “Bankrupt Vibration,” which slaps the dead face of current modern-rock radio. A completely unpretentious leap forward from 1996’s excellent Regretfully Yours, Head Trip in Every Key stands on the earlier album’s hard-pop base while adding acoustic guitars, strings, horns, raga-rock elements, and echoes of everything from Odessey and Oracle, T. Rex, and Matthew Sweet to the first Boston album (a five-second bite on “Hellbent”). “Join the circus with me,” Davis sings on “Mr. Underground,” which is catchy enough to follow “Vampire” as a single; he’s enough of a three-minute classicist to gripe about the likes of Matchbox 20 and young enough to hope he gets to keep brightening the drab airwaves with his own stuff. And he’s ambitious enough to bite a mystical title (“The Art of Dying”) from George Harrison for a seven-minute closer that, remarkably, never gets tired. If Elektra can push the best of these songs to the FM success it has found with Third Eye Blind and Alana Davis, it’ll be a fine summer around the pool.