Justin Bieber explored the musical and genre range of his still-youthful voice on his debut full-length. It features sweetly crushed-out throwbacks to street-corner R&B like the Ludacris-assisted “Baby,” plus songs with a twangier vibe like “That Should Be Me.” On the pulsing “Somebody to Love,” Bieber plays master of dance-floor ceremonies with a searching, openhearted vocal. His croon serves as a foil to Jamaican export Sean Kingston’s full-bodied lower register on the playfully island-influenced “Eenie Meenie.” Confident and hook-studded, Bieber’s first album delivers on his pop promise.