Music in action: The cast of “Little Shop of Horrors” rehearse for tonight’s opening at Danville High School. Director Beth Marlowe says she at first was reluctant to lead the musical, but the students cast were a complete surprise to her. “I really hope everyone comes out to support our young actors, and support theater. I think they will be amazed by these performances, and will really see just how hard these kids have worked. It shows.” The production is about a a down-on-his luck guy who lives and works in a flower shop on Skid Row. One day, he happens upon a strange and unusual plant — little does he know, this plant has plans of his own. The play opens 7:30 tonight, and goes up Friday and Saturday, as well, at Gravely Hall Performing Arts Center inside DHS. Tickets are $5 for students and senior citizens, and $8 for adults.