Paul McCartney’s birthday is Sunday. He’ll be 64. And while I think he can still feed himself, I have to say that after the terrific heights of his latest album, his best in 25 years or so, we definitely still need him. Happy birthday, Sir Paul.

I make fun of McCartney a lot, especially in light of his mid-period solo fluff like “Ebony and Ivory,” a low point for both him and Stevie Wonder. But it’s easy to forget sometimes the wide-reaching impact his work has had on popular music over the last 45 or so years. McCartney, as far as I’m concerned, is the patron saint of melody addicts, the guy who showed the world that you could have both the strength and the sweetness, the driving rock and the complex, head-spinning tune.

The album “When I’m Sixty-Four” appears on, Sgt. Pepper’s Lonely Hearts Club Band, is considered by many (including me) to be among the best records ever made. It’s also one of the silliest – the Beatles were never a group that spoke to the oh-so-despairing soul. But within its passages lie some of the greatest melodies in pop music, and some of the most elaborate and fantastic arrangements, and many of the best of those were products of McCartney’s vision. He’s influenced hundreds of bands and songwriters, from legends like XTC and Jellyfish to lesser-knowns like Eric Matthews and David Mead.

And I have to wonder, when he was laying down the tracks for Chaos and Creation in the Back Yard in 2004, if he became aware of that influence in ways he hadn’t before. It must be difficult to be Paul McCartney, and have everyone expect that you will live up to your own monolithic status every time out. No one could do that, but on Chaos and Creation he came closer than he has since Wings broke up, and it was a wonder to behold. It was like the old Chevy Chase line – that album was like him saying, “This is why I’m Paul McCartney, and you’re not.”

They may not seem to have a lot in common (or, really, anything), but I think the same pressure applies to Sonic Youth. They helped create the sound that later became co-opted and repackaged as “indie rock,” and for many bands, Daydream Nation holds the same status as others bestow on Sgt. Pepper – it’s a revered example of the form, to study and emulate. But unlike the Beatles, Sonic Youth have had to make do with being the unjustly ignored grandfathers, whose grandchildren outsell them 20 to one.

Here’s a shocking moment for anyone who grew up in the ‘80s. Pop open the new Sonic Youth album, Rather Ripped, and wiggle the disc out. Now take a look at the tray-card photo of the band, Thurston and Kim and Lee and Steve, a quartet again after the departure of collaborator Jim O’Rourke. Look at that picture, and take a minute to deal with just how old they look.

Thurston Moore is nearly 50. Kim Gordon is 53. Steve Shelley is the baby of the band at 42. That’s pretty old for a band that keeps calling itself Sonic Youth. Whether they like it or not, they have become elder statesmen, presiding over a scene they helped originate. If you’re listening for it, you can hear SY’s influence everywhere – 200 bands a year copy Moore’s deceptively sloppy quarter-note style, and bands like the Yeah Yeah Yeahs should be paying Gordon royalties.

Meanwhile, here they are, at the end of their major-label contract with Geffen, and selling somewhere between respectably and miserably. Rather Ripped is album 24 or so, not counting side projects and solo affairs, and it sounds like the culmination of their recent evolution – here is a more subdued, older, more concise Sonic Youth, concentrating on songs and melodies instead of noisy guitar freakouts (although those are here, too). Rather Ripped is perhaps the most adult album they have made, and they still sound like they could beat up half the bands on alternative radio.

As she has on each of SY’s recent records, Kim Gordon steps to the forefront here, turning in some of the best tunes. Opener “Reena” is a perfect example, driving and hummable, but it’s “What a Waste” that stands out, with Gordon coming as close as she has lately to her unrestrained vocal performances of old. Only a couple of songs here blow past five minutes, but the band can still take you on a knotty woodland journey in four, as they prove on “Jams Run Free.”

Of the longer songs, “Pink Steam” makes the biggest impression, remaining a tricky instrumental until around the five-minute mark. But even this one is calmer, more about gentle ripples than tidal waves. The album ends with “Or,” a brief, spoken meditation over a sparse instrumental bed – where prior albums ended with an epic flourish, like “The Diamond Sea” on the incredible Washing Machine, this one kind of dissipates. It’s a remarkably restrained ending to a remarkably restrained disc.

Is this a sign that the Youths are growing too old? Not on your life. In fact, the album’s focus gives it strength – SY’s semi-improvised style can often lead to unfortunate wanderings, but here, everything is tightly wound and purposeful. Rather Ripped is the band’s most direct album in… well, pretty much ever, but it still sounds like Sonic Youth, and the quartet is still running laps around its imitators. Only a band that’s been together as long as SY has can play like this, like one single entity with eight arms and three guitars. The up-and-coming twenty-somethings can’t touch them – they get the garage-band style, but not the complexity, not the skill, and not the telepathic connection between the players.

Of course, they’ll never get the credit or the commercial success they deserve, but isn’t that always the way? At this point, I don’t even know if they want it. But I like them even more now than I did when they were young and hungry – now they are old and wise, making music for its own sake, and while they’re unlikely to cause another seismic shift in the landscape, they’re still living up to their own legacy. Rock stars growing old with integrity – what a concept.

Next week, Keane.

See you in line Tuesday morning.