I realized the other day that I am now living the most un-rock-‘n’-roll life I have ever lived.

I get up at 5 a.m., run three miles on a treadmill, shower, put on a tie and go to work. I look at the stock pages to see how my company is doing. I work all day at a desk, moving numbers around on spreadsheets and filling out paperwork. I go home, watch the news, and I’m usually in bed by 9 p.m. By all outward appearances, I have become (gasp) an adult, a transformation that sometimes amuses and sometimes horrifies me.

I do feel lately like I’m growing up, even when it comes to my artistic choices. It’s been a long time since youthful energy, bottled and served up raw, has done it for me. I hate the whole garage-rock thing, mainly for its lack of subtlety and skill. The Strokes, the White Stripes, the Hives – I personally can’t wait until they all go away. I much prefer the sedate beauty of “aging” types like Aimee Mann and Terry Taylor, or even the highly technical power of Slayer and Slipknot, to the loud, sloppy, three-chord dreck that purports to speak for the younger generation.

For the most part, I’ve embraced that side of me. I like it when artists grow up, when they pull all that teenage energy into some shape and begin to wield it. I like Bob Mould’s solo stuff more than Husker Du. I prefer Houses of the Holy to any Led Zeppelin album before it. I like later Frank Zappa works like You Are What You Is and Civilization Phaze III more than his revered stuff with the original Mothers. My favorite Alarm album is Change, not Declaration or Strength.

I love it when bands outgrow their original concept. Word is that Green Day is putting out a rock opera this year, complete with nine-minute songs and extended instrumental passages. I know, I really do, that this will be terrible. And yet, just the idea of a band like Green Day, known for lazy two-minute pop-punk hit singles, stretching those conceptual muscles is oddly fascinating to me. Stylistic progressions just knock me out.

The Beastie Boys are another group that have joyously outgrown their own concept. Of course, when your concept involves three Jewish boys from Brooklyn laying down old-school rhymes about sniffing glue, well, you’ve got a limited shelf life to begin with. If you wanted to get a good laugh out of someone in 1987, you could have told them that the Beasties would one day be one of the most respected outfits on the planet, churning out brilliant, five-star albums with a kinetic flow and a politically aware attitude.

It’s been a surprising ride from “your mom threw away your best porno mag” to “I’m sending loving light to all that is,” but the Beasties have gradually evolved into the poised elder statesmen that they are. The Boys are all pushing 40 now, and if you consider that the word Beastie originally stood for Boys Entering Adolescent States Towards Internal Excellence (really), well, this is a group that barely resembles its past self. Diamond, Yauch and Horowitz are revered these days for their sophistication and musical adventurousness, traits that barely appeared on their multi-platinum debut, Licensed to Ill.

And yet Licensed remains their biggest seller. Whenever the B-Boys are mentioned in the mainstream media, you can bet the lyrics to “Fight for Your Right” will be quoted. People seem determined to define this searching, restless band by their past. And here it is, 2004, and the Beastie Boys have finally decided to let them. They’ve created the logical follow-up to their debut with their sixth record, To the 5 Boroughs, and while it’s a fun jam, I can’t help but feel a bit let down.

Don’t get me wrong, I love the Beasties’ classic-style rap, with their lyrics that deftly tread the fine line between clever and stupid. But I also love the funky instrumentals they’ve become so good at, and the minute-long punk outbursts, and the acoustic interludes, and the newfound melodic melancholy they debuted on 1998’s Hello Nasty. The best Beastie albums, to my mind, have a patchwork, mixtape quality to them that flips you from one style to another recklessly. Try to find the common thread between the 20 songs on Check Your Head. Can’t be done, and that’s part of its scrappy charm.

To the 5 Boroughs sounds very much like Hello Nasty with all the really interesting bits cut out. It’s an entire album of “Intergalactic” and “The Negotiation Limerick File,” and it represents the B-Boys’ first absolute commitment to one style of music. Boroughs is 15 two-to-three-minute hip hop tracks, all beats and rhymes with little variation, and it’s over in 43 minutes. And they could barely sustain that running time – had they let a few more experiments on board, weaker tracks like “Shazam” and “The Brouhaha” probably would have been dumped.

But that’s just about all the negativity I can spare for this record, because it is a passel of fun. If you harbor any doubts that rap is a storied genre with its own rich tradition, equivalent to classic rock, this album should dispel them. It’s as much a retro pastiche as any record by the Black Crowes, and just as precisely and lovingly crafted. (The preceding analogy just happened to compare two of Jeff Maxwell’s favorite bands, and I’d bet he’s grinning right now.) This is Run-DMC, Grandmaster Flash and the Sugar Hill Gang, ever so slightly updated but just as enjoyable.

Mike D, AdRock and MCA are still in a class of three when it comes to dumb-witty good-time lyrics. The superb opener, “Ch-Check It Out,” all by itself contains these doozies: “Believe me when I say I’m no better than you, except when I rap, so I guess it ain’t true,” “I’ve got class like Pink Champale,” and “Stuck in your ass is an electrician.” It also sports the record’s funniest moment, when AdRock compares himself to Miss Piggy and his bandmates reply, in perfect imitation, “Who, Moi?”

(The runner-up: when Diamond kicks off the last verse of “Triple Trouble” with, “What the Helen of Troy is that?”)

As the title suggests, To the 5 Boroughs is also the Beasties’ valentine to New York City, and here’s where signs of the group’s maturity can be seen. The song around which all the others pivot is “An Open Letter to NYC,” which celebrates the diversity of the Big Apple over a throbbing Dead Boys sample: “Brownstones, water towers, trees, skyscrapers, writers, prize fighters and Wall Street traders, we come together on the subway cars…” As you’d expect, the specter of 9/11 hangs over this record (“Two towers down but you’re still in the game”), but the overall tone is one of hope and togetherness.

Elsewhere, the Boys get political, calling to “impeach Tex” and for a “multilateral disarm.” The thing is, their politics carry the same subtlety as their old-school boasts, which is to say none at all. I agree with the sentiments on To the 5 Boroughs, but the simplistic way they’re delivered is grating. Still, perhaps directness, no matter how clumsy, is the best way to motivate a populace that, when it comes to the Bush administration, remains like James Bond’s martini: shaken, but not stirred.

I can’t help but conclude, though, that all of this grown-up talk would work better if the Boys hadn’t decided to be 18 again musically. To the 5 Boroughs is an interesting regression, one that finds the Beasties unsure of just how mature they should be. They’ve never made a record like this one – usually they are Beastie Boys trying to be men, but Boroughs casts them as Beastie Men trying to be boys again.

Sonic Youth is another New York band that seems trapped in time by its name. In the world of feedback-drenched alt-rock, these guys are the Rolling Stones. The “Youth” in their name has been ironic for some time, especially since they began moving in a more sedate and artful direction on 1995’s Washing Machine. The waves of crashing noise are still here, but lately they’ve been nudged into more meditative directions, and the songs have grown some lovely melodies.

Unlike the Beasties, who are resisting age with all their might, the members of Sonic Youth know how to grow old gracefully. With last year’s swell Murray Street, they welcomed frequent Wilco collaborator Jim O’Rourke to their ranks, and he seems to have smoothed the Glenn Branca right out of them. The result is a fresh, airy Sonic Youth, one that doesn’t jam as much as paint with tones. And as good as Murray Street was, their second O’Rourke album, Sonic Nurse, is even better.

Sonic Youth has always written in a language all their own, and songs that sound like random jams at first gradually reveal themselves as minor guitar symphonies, meticulously arranged. One odd side effect of this language is that once one immerses oneself in Sonic Youth to the point of figuring it out, it’s hard for one to go back to just about anything else. The songs on Sonic Nurse are easier to figure out and love than those on, say, Evol, but the underlying structures are just as twisty and mindbogglng.

Kim Gordon is back out front here after her minimal showing on Murray Street, and her half-screamed vocals provide this album’s only real link to the band’s early sound. It’s been a gradual progression to this point, but Sonic Nurse is a quieter, cleaner piece of work than just about anything SY has done. That’s not to say the intertwining webs of guitar are not here – just check out the extended instrumental second half of “Dripping Dream” – but that the tones are more hushed and considered, and the melodies sweeter and more plentiful.

And the result is a clarifying of the band’s modus operandi. Here the odd tunings, the bizarre chord phrasings, and the tonal interplay reveal themselves as compositions, not just improvisations. These are songs that could only be played by practiced and proficient musicians, and similarly, by bandmates who share a tremendous bond. There is power in the way the members of SY listen to each other and anticipate each other’s moves, especially when playing such tricky and dense music. And of course, the only way musicians and bands achieve such a level of skill is by living long enough and playing long enough. The upside of age is mastery, and Sonic Youth is a prime example.

Sonic Youth and the Beastie Boys have had similarly lengthy careers, and both acts have taken their original sound places that one would never have guessed they could go. It will be no surprise that in a country obsessed with youth, To the 5 Boroughs will be a massive success. But at this stage of my life, when I’m learning how to accept my age with some measure of grace, I take comfort in hearing works from long-running bands that are figuring out the same thing. Sonic Nurse is such a work, deeply textured and mature, the kind of record I will reach for well into my thirties, while To the 5 Boroughs stays on the shelf, forgotten, except as a pleasant reminder of a time left behind.

Next week, Wilco.

See you in line Tuesday morning.