It’s standard practice these days to wonder what happened to the promise shown so early by Nas. It seems that as often as he’s changing his name, he’s also changing his attitude toward his art. On Nastradamus, the second album he’s released this year (after the more or less introspective I Am), Nas offers more grandeur, less neighborhood. When he does delve into his own experiences, he is, as always, a gorgeous lyricist, delivering nuanced, unforgettable descriptions of places and people. But the album also includes more pop-inflected tunes, with hooks and danceable beats. The wunderkind Nasir Jones who dropped the extraordinary Illmatic way back in 1994 has matured, into a slick businessman and performer.

The new album opens with a shout-out to his “brothers and sisters, welcome to our time,’’ observing the ascendency of hiphop and his own significant part in it. This is followed by a spoken word piece by sublime slam poet Jessica Care Moore (“Nastradamus tell us how the story gets told”), who also closes the album with a call for self-awareness (“Never count your blessings with haste / Even a prophet can catch a case”). And yet, the first single released as a video, “Nastradamus,” goes all gimmicky, with 3D imagery (if you’ve got the glasses) and futuristic tough-guy-posing.

Now Nas is working with popular, proven producers, like Dame Grease (DMX and Tricky’s excellent Juxtapose) on the haunting “Some of Us Have Angels’‘; Timbaland; DL Premier (for the gangster-bravado tale, “Come Get Me”); and Mobb Deep’s Havoc (“Shoot Em Up,” using a kind of “12 Days of Christmas”-lite beat to list the many ways to die in the hood). L.E.S. produces several tracks, including “Last Words,” which relates the desperate infinity of prison life (by provocatively taking on the “persona” of the prison itself): “No matter your age, I can shatter you, turn you to a savage enraged ... Yo it’s stunning when bed sheets become the woman.” These are boldly sad and desperate impressions, but they leave out a critique of the justice system, which is all about people and prejudice.

It’s clear that the man is skilled and mad-prolific. Throughout the album, Nas veers between tiresome boastfulness and fine lyricism. And his moments of self-reflection can be potent, as when, in “Life We Chose,” he wonders, “What’s real, when you talk behind a man’s back, then you see him and give him dap?” or in “God Love Us,” when he observes, “Those who know, don’t talk, and those who talk don’t know a thing.”

But mostly, he insists on his pose, which has developed in a way that seems more commercially savvy than rooted in any NYC round-the-way experience. On “Nastradamus,” he reminds us, “I’m a wild barbarian… Felonious / My description is doo rag pants sag down to my feet / AK is my heat ... Till I lay six feet.” And while, on the conventionally patronizing “Big Girl,” he may sound just a little too Bones-Thugs-ish, on other tracks, his unnecessarily hyperbolic boasting turns all-out absurd, as when he teams with Ginuwine for the silly I’m-a-sex-god anthem, “You Owe Me” (“Fantasizing me inside and you ridin’ / Throw it like a stallion”), including the ridiculous idea that the fortunate shorty will “Owe me back like you owe your tax / Owe me back like forty acres to blacks.”

Nas shows flashes of his early assurance and ingenuity here, but the album is, finally, uneven. It might be that the moral is that speed, insight, and intensity can only go so far, that, after all, taking some time to make art has its rewards.