Elliot White is a 16-year old musical savant with Asperger's Syndrome. After his mom's sudden death, Elliot is forced to leave his performing arts high school in New York City and relocate to Winslow, Arizona to live with his eccentric aunt, Amaryllis Long. When Elliot discovers his new high school has no music program, he decides to form his own band of musical misfits, who it turns out, are unable to attract an audience. This is when Amaryllis inspires Elliot by giving him some mustard seeds, explaining that faith as small as a mustard seed can move mountains. As their faith grows, Elliot and his band-mates begin to believe they will be able to give a public performance, but the school's principal, Mr. Winters, who just cut all of the arts programs, stands in their way.