Joe Chvala got into dance to become a more versatile theatrical performer, but dance soon became central to his own art. Karla Grotting was one of the founding members when, in the early 1990s, Chvala formed his Flying Foot Forum dance-theater company. Chvala and Grotting are detouring from the full company to produce their first evening of duets. 3-Minute Egg went to a dress rehearsal for The Circus of Tomorrow and Tomorrow, running through April 26 at the Southern Theater.