By Chris Brook

By the time Nas took the stage at Matthews Arena Saturday night, it was clear the ears of the 4,000-strong Springfest crowd had perked up.

With a large banner proclaiming “Hip Hop is Dead” draped over the scaffolding behind him, the Queens-born and bred rapper tore through an hour-long set that highlighted his 15-year eminence in the genre, including tracks from his near-legendary CD Illmatic and a deluge of late-’90s radio singles.

With his DJ’s turntables housed in a black casket accented by white floral arrangements, Nas – whose real name is Nasir Jones – welcomed this year’s Springfest audience to “the funeral.” The MC has been using this metaphor for recent lack of compassion in rap music, mainstream radio and pop culture. Gold necklace included, everything about Nas’ set commanded an air of respect. The one-two punch of 1994’s “N.Y. State of Mind” and “Represent” were straight to the point, pleasing longtime fans as prime examples of the rapper’s unflinchingly gruff delivery. When prompted, the audience raised fists (“Hip Hop is Dead”), formed guns with their hands (“Got Ur Self A Gun”) and even as Nas dropped to his knees during the pseudo-idyllic “One Mic,” the crowd became a sea of lighters and cell phones.

Donning a Queensbridge Housing Projects T-shirt to honor his roots, the rapper known in some circles as “Nasty Nas” wound his tightened rhymes around a few bars of “Street Dreams,” “Nastradamus,” and the song whose video caused controversy in the heyday of MTV’s Total Request Live, “Hate Me Now.”

Nas wound his set down with many audience members leaning over barricades, pumping their fists and chanting along to his 2002 single “Made You Look,” before ending with one of his biggest crossover hits, 2003’s optimistic “I Can.”

Gym Class Heroes performed third and warmed up the stage by playing their own brand of alternative hip-hop with live instrumentation. The quartet played a healthy hour-plus set of songs from their albums As Cruel As School Children and The Papercut Chronicles.

The band arguably didn’t fully hit their stride until they played their Billboard hit “Cupid’s Chokehold” and follow-up single, “The Queen and I.” Regardless, lead singer Travis McCoy kept the audience laughing by waxing poetic about John Cusack, running red lights in Brooklyn and Sylvia Plath in a freestyle rap. They rounded out their set with “Taxi Driver,” in which McCoy name-dropped bands like Death Cab for Cutie and last year’s Springfest headliners Dashboard Confessional, and also “Clothes Off!” a song McCoy hoped would “incite a dance riot” but failed to get people into the aisles.

Wasalu Muhammad Jaco a.k.a. Lupe Fiasco also helped open the show, running through a tepid hour-long set of songs from last year’s Grammy-nominated CD, Food and Liquor. While he put his all into jumping around stage, Fiasco’s socially conscious rhymes didn’t fire on all cylinders. After rapping along to songs by Kanye West, Jay-Z and oddly enough, the Gorillaz, Fiasco performed one of his mixtape songs “Switch,” and the cringe-worthy “Sunshine,” before passing the mike to new prot