"The Times They Are A-Changin'," the Broadway musical concieved and directed by Twyla Tharp to the music of Bob Dylan, closed Sunday after 63 performances, including previews. Only one number gave us a taste of what might have been. For "Rainy Day Women #12 & 35," Tharp gave us a meaty dance segment with exercise balls (painted to go with her circus setting), danced in perfect unison by her ensemble of virtuosos. The lyric "Everybody must get stoned" seemed to give the choreographer permission to loosen up and stop sellin' it "Broadway-style"... and we finally got some sincere and even funny moments. When Tharp next returns to Broadway, here's hoping the whole show hits such a high note.