The “co-opera” collaborative venture between Cal Poly’s Student Opera Theatre and Opera San Luis Obispo continues this year with a complete production of Franz Lehar’s comic operetta “The Merry Widow,” with libretto by Ross Halper. Outstanding student singers in several key roles will perform side by side with internationally acclaimed opera singers. Student instrumental musicians will perform with OperaSLO’s professional orchestra. Tickets ($18 general, $16 seniors, $9 students)