Ever since a 17-year-old Nasir Bin Olu Dara Jones appeared on Main Source’s 1991 classic “Live at the Barbeque,” hip-hop would be irrevocably changed. Nas. Gifted poet. Confessor. Agitator. Metaphor master. Street’s disciple. Political firebrand. Tongue-twisting genius. With music in his blood courtesy of famed blues musician father Olu Dara, the self-taught trumpeter attracted crowds with his playing at age 4, wrote his first verse at age 7 and, with 1994’s Illmatic, created one of the greatest hip-hop albums of all time before he could legally drink. Two decades on, Nas remains an incendiary, outspoken and brutally candid rapper on the recently released Life is Good, his tenth album and sixth to debut at the top of the Billboard 200.