'Pac didn't see himself 'growing old,' his friend and fellow MC tells MTV News on what would have been Shakur's 39th birthday.By Mawuse Ziegbe, with reporting by Sway Calloway Naughty by Nature's Treach Photo: MTV News Tupac Shakur's legacy still looms large in music more than 13 years after his untimely death. You can suss out 'Pac's swagger in everyone from DMX to Ja Rule; Kanye West continues Shakur's tradition of being outspoken; and rappers still turn to his back catalog for insightful verses to graft into hip-hop hits. Part of the reason Shakur's presence is still felt is because the controversial icon left behind a hefty amount of music, including a formidable collection of unreleased recordings.