Summers in and about Washington used to be hot, humid and hopping with dance. This year’s weather has been temperate and, probably for reasons that have nothing to do with temperature or moisture, the area’s open air theaters aren’t particularly interested in presenting dance. Wolf Trap is offering a little (Riverdance and American Ballet Theatre’s “Romeo and Juliet”) and Carter Barron is still promising the season’s schedule “soon”. All the more reason to be grateful for Diane Coburn Bruning’s project – a small, summer-only company of dancers on annual vacation from their regular fall-winter-spring work. Not hidden in the pit but sharing the stage are musicians - two types during the current run, either a string quartet or a brass marching band. Repertory for performances through June 26 consists of four dance pieces and two primarily musical ones.