Is Nas the greatest rapper of all time? That's a loaded, highly debatable question, of course: From Kurtis Blow and Big Daddy Kane to Lil Wayne and T-Pain, everyone's got a rhyme-splitter-spitter -- Biggie, Jigga, Scarface Rakim or Snoop; Ghost, Em, Big Pun, 'Pac and Posdunos -- who they think has spun flax into the most durable gold on the microphone.

But no one can deny that Nas -- Nasir Jones, favorite son of the Queensbridge projects -- belongs near the end of the conversation. First, it's been 15 long years since he dropped a stone masterpiece as a debut; "Illmatic" is still regarded as a top-10 desert island hip-hop record. Since then, he's released at least two or three other four-star outings, including "God's Son" (2002) and "Hip Hop Is Dead" (2006). He's got a flow that kicks with both speed and precision -- you tumble for the jolt but can still catch the words -- and cherry-picks the best attributes of visceral, violent, gangsta rap and heartfelt, socially consciousness backpacker morality plays. He takes stylistic chances without losing his identity.

When he visited First Avenue last year, it was to drum up support for his failed experiment in overtly political hip-hop, entitled simply "Nas," after his original name for it, the racially noxious N word, couldn't sell platinum in polite company. Turns out the title was the least of its problems, and the song most likely to endure is the neo-novelty coronation, "Black President."

No matter. Whether he's got the entire crowd chanting to "Illmatic" joints like "New York State of Mind," "Represent," "One Love" and "The World Is Yours," or slamming newer material across such as "Hip Hop Is Dead," the gun-happy "Made You Look," or the paean to his Mom, "Dance," Nas doesn't simply coast on the quality of his back catalog in concert. Instead, he re-engages with the lyrics in these numbers and back it up by connecting with his audience between songs. I can't think of a better primer for a hip-hop neophyte, be it "One Mic," "Hip Hop Is Dead" (check the "In a Gadda da Vita" cop) or the uplifting "The World Is Yours."

The opener isn't too shabby either: Damian "Jr. Gong" Marley, son of Bob Marley and collaborator with Nas on the upcoming benefit record for African schoolchildren, "Distant Cousins."

Nas and Damian Marley, at First Avenue, Tuesday, June 30, 8 p.m., $36.