In Meagan Brothers's "Supergirl Mixtapes," a music-obsessed girl travels to New York City to find herself.After years of boredom in her rural South Carolina town, Maria is thrilled when her father finally allows her to visit her estranged artist mother in New York City. She's ready for adventure, and she soon finds herself immersed in a world of rock music and busy streets, where new people and ideas lie around every concrete corner. This is the freedom...