Review: Twyla Tharp Dance celebrates 60 years with something old, something new in stunning night at the Harris

It starts where “In the Upper Room” ends.The opening image of Twyla Tharp’s newest dance, “Slacktide,” is a single dancer, facing upstage, a beam of white light illuminating only his forearm. He slowly, methodically, closes his fist and draws his elbow down toward his waist. It’s a fist pump. A transposition of the final moment in Tharp’s 1986 tour de force.For “Slacktide” — which forms the back half of Tharp’s 60th anniversary “Diamond Jubilee” running through Saturday at the Harris Theater — the prolific choreographer revisited composer Philip Glass for the first time since “In the Upper Room.” A thrilling interpretation of Glass’ 1999 half-hour score “Aguas da Amazonia” has been realized by Chicago-based Third Coast Percussion, who play live at the Harris with Chicago flutist Constance Volk.Third Coast, by the way, is celebrating a milestone of its own, releasing a 20th anniversary album Friday with works by Jlin, Tigran Hamasyan, Zakir Hussain, Jessie Montgomery and Musekiwa Chingo...