It's hard to believe that Koresh Dance Company has been performing on Philadelphia boards for almost 25 years. Harder still to think that Melissa Rector is still shining in every performance as she has since 1991. And hardest of all not to be moved by

Aftershock

, artistic director and founder Ronen Koresh's love letter to his adoptive homeland. It opened the company's spring run at the Suzanne Roberts Theatre on Thursday night.

Aftershock is episodic, deriving perhaps from Koresh's biography. The oldest of five children, he was born in Israel and began his dance career in the second company of the world-renowned Batsheva Dance Company. That was interrupted by compulsory military service - in which all his siblings also served. He left for New York to join Alvin Ailey's dance school a month after his service ended. So military motifs often pepper his choreography.

Aftershock's 13 titled sections begin with "Then," move through "Change," and end in "Aftershock." But instead of his usual big-bang, full-cast finale, Koresh surprises us with a poignant duet for Shannon Bramham and Rector, bathed in Peter Jakubowski's joyous polka-dot lighting.

Don't worry. Koresh brings the full company out together in the penultimate section, "Whiplash." And it's a stunner - presenting not pretty moves, but awkward, angular, sharp ones - elbows up, shudders, insane belly scratching.

I especially loved the two opening full-cast numbers. Most of the current 10-member ensemble have been in the company for several years, and they are dancing together as smoothly as a well-tuned Lamborghini. Koresh masterfully doubles their look by massing them center stage in double lines of three diagonally, with Joseph Cotlar filling up the space on one side and three dancers in a triangle on the other. They march and drill, lunging to the side to cataclysmic music by Mozart and James Blackshaw and a poetry recitation by Karl Mullen mixed over it: "The biggest shock of all is who we are."

Outstanding moments include Robert Tyler gracefully mirroring one of the women, to the fingertips, to music by Gregory James Smith and the trio called "Change," with Asya Zlatina, Kevan Sullivan and Fang-Ju Chou Gant. Flowing one from the other, three love duets ranged from the light romantic, with Cotlar and an elegant Krista Montrone, to a sexy, French-flavored tango with Jessica Daley and Tyler. And, in a darkly dramatic duet called "Alive," Rector and Micah Geyer seem on an ambivalent journey that ends in tender acceptance.