BASSH at the Lobero

A SWAT team storms the stage; ball gowns sparkle; dancers entwine their limbs mid-air; Barbie comes to life and turns out to be a saucy, street-savvy, in-your-face kinda girl.

Now in its 11th year, the Dance Alliance’s annual showcase of popular forms has risen from a grassroots production to one so polished and glittering you almost forget these are amateurs.

As in years past, styles ranged from ballroom to swing, salsa to hip-hop, and though many of the performers were the usual suspects, their performances were pumped to a new level of professionalism. Chalk it up to the ever-growing popularity of TV shows like So You Think You Can Dance or simply to the dancers’ deepening commitment to their art form; it made for an evening of great entertainment. For BASSH 2011, even the acronym itself got a makeover—the “A” that used to stand for Argentine tango this year represented aerial dance.

Hip-hop claimed five of the 18 slots this year, and while that form is often aggressive, violence was a clear theme. In “Lights Out,” performer and choreographer Cynthia Norton got attacked by a crew of snarling b-girls, while the ever-intense Tamarr Paul led a tight team of dancers in bulletproof vests on a hunt for a convict in an orange jumpsuit in “America’s Most Wanted.” And in a nightmarish scene straight out of The Twilight Zone, the dancers who had seemed to represent normalcy in “Eye of the Beholder” whipped off their surgical masks to reveal pig noses.

The drama rose even higher with “Airealistic Duo,” in which aerial dancers Carmen Curtis and Sunny Soriano wrapped and rewrapped themselves around one another, and “Opuesta,” for which Ninette Paloma and Emily Garvin dropped their flowing shifts to the floor and swung through tricky trapeze maneuvers like they were born to fly.

It wasn’t all shock and awe. Longtime BASSH emcee Derrick Curtis offered up a refined foxtrot and a sexy rumba, James McGann and Teresa Johnson convinced in “Romantic Passion,” and the crowd went wild for “Tied Up,” a Latin fusion number for which Hector Sanchez and Lauren Breese wore fishnet shirts covered in silvery threads, and seemed to ensnare each other as much with seductive writhing as with chains.

When amateurs take the stage, the measure of success isn’t really in how pro they look; it’s in how much joy they bring to the dance. This year, though, sleek costumes and tight choreography matched the through-the-roof enthusiasm. How high can this thing rise?