Breaking up is hard to do. Except when it isn’t. The tour for Luna’s seventh studio album, “Rendezvous,” which brought the band to Irving Plaza on Saturday night, is also a farewell tour. After 13 years as a mainstay of the New York indie rock underground, Luna is disbanding. But this isn’t the end of an era so much as the final aftershocks of one that ended long ago.

Drenched in green and purple stage lights, Dean Wareham looks as though he hasn’t aged a day in 15 years. That’s when we first saw him, with his moody, drowsy, hip band Galaxie 500. If Nirvana hadn’t blown the whole world wide open, they might have been stars. They were big in England. But instead, they split up, and Wareham began his long keeper-of-the-flame campaign, nurturing a new, more sensitive underground.

He still dresses in a style that might be called “postgrad chic”: a wrinkled, collared shirt, perfectly mussed hair, tightish jeans (sometimes white), and vaguely European sneakers. It’s subtle signaling, but it’s the little things that give it verve. Except for the deepening of a few grooves in his face, he’s as thin and young and cool as ever.

His music has remained the same also. The night’s set drew from the band’s entire career, but resorted to the same sublime, chiming guitars that echo the other great, never-fully-appreciated-in-their-own-time New York rock acts – the Velvet Underground and Television. Sean Eden’s histrionic guitar solos sometimes enlivened the songs, but they felt a little out of character, as if they were trying just a bit too hard.

Wareham’s words fall somewhere between pretentious cafe poetry and verbal doodles. “Burning windshield. Denim suit. Broken glass. Snake skin boot.” He delivers them in an expressionless baritone that aspires to the anti-virtuosity of Stephin Merritt, Calvin Johnson, late Leonard Cohen. It’s so cool and bored.

Luna’s music has always been a study in insouciance, and at the height of their career in the mid-1990s, it served as a counterweight to and respite from the overblown angst ushered in by Nirvana (but made phony by their acolytes). Along with other college rockers like Pavement, Stereolab, Yo La Tengo, and Belle and Sebastian, Luna carved out a space for the hyper-literate – the effete elite – that was a true alternative to brawny “alt rock.”

The height of their craft and the peak of their career was 1995’s “Penthouse,” a spacious and spacey album filled with lush guitar melodies and episodes of minor importance. The song “Lost in Space” seemed to encapsulate everything about the band. Over an exchange of velvety wah-wahing guitars, Wareham sings: “it’s true you’re lazy, you’re tired and crazy / and you know there’s something more, but you can’t give it a name / someone’s selling all your heroes and they seem so tame.” That’s just what Luna set out to be: tame heroes.

Without anyone really noticing, this era ended abruptly in 2001 with the arrival of the Strokes and all the rest. Interpol, the Yeah Yeah Yeahs, the Liars. All the loud and pretty rock bands reclaimed the underground from the frumpy and plain and awkward and soft-spoken people.

The crowd at Irving Plaza on Saturday belonged to this earlier era, and they seemed to relish being back in their environment, among their people: 30-somethings wearing long sleeve shirts under short-sleeve T-shirts, with thick glasses, frail features, and thinning hair. They knew every guitar lick and danced in a way that showed they were anticipating the next note. If Wareham seemed bored, he was the only one.

In typical Luna fashion, the band posted a sardonic list of ten reasons why they were breaking up on its Website: (no. 1) “Rock and Roll is killing my life,” (no. 2) “The Universe is Expanding,” and (no. 5) “Too many hands to shake, that means germs.” The real reason may have been expressed in a lyric performed Saturday: “I don’t want to ride that bus / I am tired of all of us.”

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Coming 12 years after Public Enemy partnered with Anthrax for “Bring tha Noise” and 18 years after Run-D.M.C. broke the rap-rock barrier with a remake of Aerosmith’s “Walk This Way,” Jay-Z and Linkin’ Park aren’t exactly pioneering anything with their new collaboration “Collision Course.” But the combination is intriguing. After all, Danger Mouse created a sensation layering lyrics from Jay-Z’s “Black Album” over beats culled from the Beatles’ “White Album,” and Linkin’ Park’s entire sound is built on a rap-meets-rock formula.

The project began small with a plan to rework a few songs for a new MTV concert program called “Ultimate Mash-Ups,” but after some encouraging early results, they decided to flesh it out into a six-song EP (it also includes two bonus live tracks). And while it’s unlikely that fans of either camp will prefer these versions to the originals, the album does contain some interesting lessons about blending the two genres.

One of the best songs on Jay-Z’s “Black Album” – “99 Problems” – uses a big booming rock riff behind his lyrics (compliments of Rick Rubin, the same man who introduced rock to Run-D.M.C.’s sound 20 years ago). Here the same approach yields the best results.

The first track, “Dirt Off Your Shoulder/ Lying From You,” gets underway with Linkin’ Park MC/vocalist Mike Shinoda rapping his own lyrics over the beat to “Dirt Off Your Shoulder.” The result is silly and a little embarrassing for all involved. But after a verse, the sides switch roles and everything falls into place: Jay-Z’s lyrics sound great over Linkin’ Park’s fuzzedout guitar sample, and Chester Bennington throat-shredding singing adds a welcome intensity.

This is the pattern throughout. “Numb/Encore” succeeds by framing Jay-Z’s familiar flow with pinging midi-pad notes and piano. But it’s hard to imagine what compelled Shinoda to rap his own feeble lyrics over the beat of “Big Pimpin.” This is career suicide for any MC, let alone an unskilled white one. He does better when he resorts to rap karaoke, as on “Points of Authority/99 Problems/One Step Closer,” where he performs Jay-Z’s rhymes for him, changing the words – “my” to “his,” “I’m” to “he’s” – so as to praise the original author.