Velocity Dance Center is celebrating the 10th anniversary of this summer event and the dance workshop that feeds it. Based on the idea that Dorothy was right, there’s more than enough going on in your own backyard, “Strictly Seattle” draws its instructors and choreographers from the local dance community, setting them loose in a three-week intensive. Seasoned dancers have been honing their skills and newbies have been testing the waters—a combination of them all performs in a showcase with choreography by Paige Barnes, Rob Kitsos, Amii LeGendre, Adele Myers, Amy O’Neal, and Deborah Wolf.