dancer to all take the stage at the same time), changing the judging structure (e.g. having a specific guest judge), or changing the time limits (e.g. a "1-2-3" slam with three rounds of one minute, two minutes, and three minutes, respectively). Although theme slams may seem restricting in nature, slam venues frequently use them to advocate participation by particular and perhaps underrepresented demographics (which vary from slam to slam), like younger poets and women. Poem Poetry slams can feature a broad range of voices, styles, cultural traditions, and approaches to writing and performance. The originator of performance poetry, Hedwig Gorski, credits slam poetry for carrying on the poetics of ancient oral poetry designed to grab attention in barrooms and public squares. Some poets are closely associated with the vocal delivery style found in hip-hop music and draw heavily on the tradition of dub poetry, a rhythmic and politicized genre belonging to black and particularly West Indian culture. Others employ an unrhyming narrative formula. Some use traditional theatrical devices including shifting voices and tones, while others may recite an entire poem in ironic monotone. Some poets use nothing but their words to deliver a poem, while others stretch the boundaries of the format, tap-dancing or beatboxing or using highly choreographed movements. What is a dominant / successful style one year may not be passed to the next. Cristin O'Keefe Aptowicz, slam poet and author of Words In Your Face: A Guided Tour Through Twenty Years of the New York City Poetry Slam, was quoted in an interview on the Best American Poetry blog as saying: One of the more interesting end products (to me, at least) of this constant shifting is that poets in the slam always worry that something—a style, a project, a poet—will become so dominant that it will kill the scene, but it never does. Ranting hipsters, freestyle rappers, bohemian drifters, proto-comedians, mystical shamans and gothy punks have all had their time at the top of the slam food chain, but in the end, something different always comes along and challenges the poets to try something new. One of the goals of a poetry slam is to challenge the authority of anyone who claims absolute authority over literary value. No poet is beyond critique, as everyone is dependent upon the goodwill of the audience. Since only the poets with the best cumulative scores advance to the final round