A young singer-songwriter of startling maturity, Philadelphia native Liz Longley has catapulted into the folk-pop consciousness. The recent Berklee School of Music grad possesses both a honeyed voice that immediately demands attention, and a melodic sensibility that just can’t be taught. Longley, who now lives in Nashville, has already released two acclaimed full-length records and has one coming out this year. Its much-buzzed about single, “This Is Not the End,” is already making waves on the radio. She is poised to have a breakout year in 2014.