When Nat, her best friend Jess and singing-star wannabe Harper sing together, their harmonies bring down the house. For Nat, the experience sparks a driving new desire to perform. But when the girls form a trio and enter a contest for a chance to play at the Tall Grass Music Festival, Nat finds that harmony—musical and otherwise—is hard to maintain. Her bandmates almost never agree, her new boyfriend starts behaving more like a non-boyfriend, and the trio's famous-musician mentor doesn't even like the way Nat breathes. Every day, Nat's dream of performing at Tall Grass seems farther away, and she questions whether she has what it takes to get there.
Ellie is used to getting leading roles in her small-town school's musicals, but her place at center stage disappears when her dad becomes the host of a breakfast TV show and they have to move to the big city. When Ellie auditions for—and lands—a spot with the Youth Works Theater Company, she comes up against a tight-knit group of talented, experienced and competitive triple-threat performers. Not only does she not get a lead, but she has to share a role with Marissa, a company veteran who seems determined to do all she can to outshine Ellie. Out of her depth and far from all that she's known, Ellie wonders just what she has to do to stop feeling upstaged by everyone around her.