Joseph "Jo Mersa" Marley embodies the spirit of his grandfather's song "Three Little Birds." The free-spirited 30-year-old son of Stephen Marley Joseph "Jo Mersa" Marley embodies the spirit of his grandfather's song "Three Little Birds." The lighthearted 30-year-old son of Stephen Marley approaches life in a carefree manner, and it shines through his music.