When she is good she is very very good, and when she is bad … well, even George Balanchine admitted he made some “lousy” ballets. Twyla Tharp has been very very good for ABT, and her 17th work for the company, set to the Brahms String Quartet No. 2, premieres at the opening night gala (October 16) and is performed four more times during the two-week season. And don’t skip Deuce Coupe, Tharp’s 1973 ballet set to songs by the Beach Boys. It had its ABT premiere last spring and is the best kind of time travel. Repertory includes new works by Gemma Bond and Jessica Lang, and Balanchine classics Apollo and Theme and Variations. —L.J.