At 83, choreography pioneer Twyla Tharp’s primary goal has remained the same over her 60-year career. “It is to work,” says Tharp, whose troupe appears in Berkeley on Feb. 7-9. Cal Performances’ “Twyla Tharp Dance Diamond Jubilee” includes two West Coast premieres: a revival of 1998’s “Diabelli” and 2025’s “Slacktide” set to music by […]