San Marcos Students Return to the Stage as COVID-19 Protocols Play Side Role Rehearsals and even the script require modifications, but the show is set to go on for next week's production of the musical 'Mamma Mia!' San Marcos High School students perform "Dancing Queen" during a dress rehearsal Wednesday for "Mamma Mia!" (Brooke Holland / Noozhawk photo) San Marcos High School students perform in flippers during a dress rehearsal Wednesday morning for next week's production of "Mamma Mia!" (Brooke Holland / Noozhawk photo) San Marcos High School seniors Rachel Henderson, left, and Roz Borah attend a dress rehearsal Wednesday morning for next week's production of "Mamma Mia!" (Brooke Holland / Noozhawk photo)