It was still daylight outside when the lights went up for Saturday night's concert at Dance Project, the last of the season. The performers were Deborah Riley and Diane Frank, and the collaborative piece they performed was "Overlap," a study of weight and the interaction of bodies. Riley performs with Douglas Dunn in New York. Frank, formerly of the Maryland Dance Theater, also dances with Dunn, but teaches locally as well. Together they presented a fine piece, one that was both rigorous in concept and full of physical discovery.

The first section contained very little dance movement.The two performers-one clad in monochrome brown, the other in purple-walked on stage, sat down to the floor, and proceeded to loll and lean against one another like sunbathers, shifting position occasionally in a series of listless tableaux. They looked like tangled bodies on a beach, but the mood of the passage was more introspective - as if the two were listening hard to deep visceral messages. In successive passages, they carried the notion of leaning and interdependence into ever more active permutations, until the few points of stillness became moments of punctuation in an otherwise unbroken flow of motion.

In many ways, "Overlap" is like an elegantly animated physics demontration. In one passage, the dancers leaned together from a standing position and rotated against each other, circling the performing space like cogs. In another, they demonstrated the power of inertia in a two-woman variation of "Crack the Whip." In later passages, they moved in and out of phase, resolving divergent patterns into symmetry, doubling their body space, dividing and doubling again. They worked entirely without music but the silence was riveting: a testimony to the concentration of the performers and the beauty of the images they created.