It's usually good to be wary of musical prodigies - how many little geniuses in any genre have turned into big-time flops when they reach adulthood? But Sierra Hull appears to be the real deal. The teen has already become a master of the mandolin, and has taken the bluegrass world by storm. "Secrets," her national debut, pulses with vitality as it ranges from pop-oriented ballads to traditional bluegrass foot-stompers. Her vocals sound a little fragile, but hopefully her voice will mature and strengthen with age, and her natural talents as musician, bandleader, and songwriter more than make up for any youthful shortcomings. With "Secrets," Hull has staked her claim as a bluegrass prodigy, and, while the future is never guaranteed, she has the chops and spirit to make her success last.