A unique outdoor performance that combines the graceful movements of professional dancers with the magnificent athleticism of Arabian horses will take place on Vashon this weekend.

“Dancing in Real Time,” a work by the New York City-based group The Equus Projects, will also feature music performed by Jami Sieber, an acclaimed Northwest vocalist and electric cellist, and Geoff Jones, a local percussionist.

It’s the second time the dancers have traveled to Vashon to collaborate with the highly trained Arabian horses that reside at Heather Houston’s Heart of the Horse Farm. Last year, the company performed a dreamlike piece called “Resting Ground” that honored Houston’s childhood horse.

JoAnna Mendl Shaw, who is the company’s artistic director, said this year’s performance will be more playful.

“Our mandate this year is to work in animated real time,” Shaw said, adding that the performance will be “improvisational and yet highly structured.”

“Dancing in Real Time” will feature four people and seven horses, dancing together in a process that Shaw said will force the dancers to make “hundreds and hundreds of strategic decisions” along the way. The performance will be threaded together by a solo rider, Kate Shook, a local horse trainer, and horse.

Regular performances of “Dancing in Real Time” are at 6 p.m. Friday and Saturday, Aug. 13 and 14, at 21901 Vashon Hwy. S.W. Tickets, $25, are on sale at Books by the Way, Vashon Bookshop, Heron’s Nest and www.dancingwithhorses.org. Tickets for elders and youth, $20, are also available at stores, but not online. Saturday’s show is sold out, but there will be an open dress rehearsal for the show at 6 p.m. Thursday, Aug. 12. Tickets, $10, will be sold at the door.