Northwest Dance Project dancer/choreographer Patrick Kilbane Franco Nieto

An exploding bag of microwave popcorn will provide only part of the soundtrack to Lindsey Matheis' piece in Waltzing + Wassailing, Northwest Dance Project's (NWDP) holiday celebration of contemporary dance. The kernels will pop in spontaneous a-rhythm to the powerful music of Vagabond Opera—a hodgepodge of cabaret, klezmer, gypsy, and jazz—as four leading Portland choreographers and three rising stars from NWDP's own company (including Matheis) introduce works inspired by Vagabond Opera songs.

Whether or not the show sells out, the room will be at capacity. Six musicians, between one and six dancers per piece, plus someone to serve hot wassail (a spicy cider with or without rum) and release fake snow adds up to a lot of bodies packing the 2,000-square-foot NWDP studio. I'm reminded of the seasonal activity of plugging too many strings of lights into one socket. Brightness will reign if the power doesn't go out.

Walking in on a recent rehearsal, I heard NWDP Artistic Director Sarah Slipper guiding the movements. "Kiss your knees. Kiss your knees. You want to get this arm round around this thigh... can you get under her pit?" Her practice is as much about planning as discovery, an amiable defiance of her classical ballet training. She nurtures experimentation from start to finish, as Matheis' onstage microwaving attests. Equally fervently, Slipper seeks to advance in-house talents, build her company's reputation, and combine forces with outside groups. The "who's who" list of guest choreographers for this show is a testament to her success, featuring Mary Oslund, founder of Oslund+Co dance company; Jamey Hampton, co-artistic director and founder of BodyVox; and Gregg Bielemeier, founding core member of Conduit Dance.

The collaboration on display also owes in many ways—but one especially—to NWDP's installment in the former Mississippi Ballroom space. (They've had their North Portland studio since June; prior to that, they were vagabonds themselves.) Eric Stern was a regular guest at rehearsals who used to sit quietly by the parquet, reading a newspaper while his kindergarten son watched intently. Until one day he made his interjection: He started singing along to rehearsal music, the aria from Bizet's The Pearl Fishers. Mr. Stern, it turns out, is the leader and tenor vocalist of Vagabond Opera. And so, in this rapidly yuppifying neighborhood, another creative baby was born.