One of the great things about music, as opposed to movies, is how an album can slowly creep into your life without warning. While a film is something you go and sit in a theater to watch one time, an album (ideally) is something you spend several days and weeks with. It becomes a more permanent addition to your day-to-day world. Music infiltrates your moods; it becomes the way you amplify your anger, unhappiness, love, and joy. Why else could a song from a junior high dance still be able to knock you sideways when it comes on the radio dozens of years after the fact? Somehow, without you knowing it, that emotional tattoo remains.

Likewise, albums can sometimes conceal their surprises for months, just waiting for you to find them. And when you do, it's like stumbling onto buried treasure. You want to shout to the heavens. You want to show it off to everyone.

In other words, here's a piece on Paul Westerberg's terrific new Stereo/Mono album - almost five months after it came out.

Why did it take me so long? Well, a little backstory...

Westerberg's legend is well established and slightly misleading. He forms the Replacements in the '80s, becomes famous for his passionate and messy songs, and embraces a drunk-and-unprofessional attitude (which elevates him into an indie keepin'-it-real god). Then, the band gets signed to a major label, they start to suck, they break up, he gets sober, he goes solo, he really starts to suck and only gets older and lamer. Going going gone.

If the first half of his legacy is overstated, then the second is far from fair. The Replacements were, at times, a great band, but I could never fully accept their so-sloppy-you-gotta-love-'em purity. Let It Be, from '84, is the band's peak, but it's not quite a classic - it's still too slapdash and hangdog to get out of its own way.

Conversely, Westerberg's solo career has been better than critics admit. His first post-Replacements effort is still his finest hour on record. Yes, 'Mats fans, I'll take 14 Songs over Let It Be or Pleased to Meet Me or (god help you) Tim. 14 Songs is where maturity and songcraft converge. The rockers aren't as good as the ballads, but all his moods are well represented: heartsick romantic; caustic smartass; throwaway, mercurial charmer; unspeakably beautiful songwriter.

The rest of his solo albums haven't matched it. Mostly, they feel like stumbles in the dark to achieve a barely comparable result.

Stereo (and its companion piece, Mono) don't make that mistake, but it took awhile to figure out what makes them great. With their lo-fi design - both discs were culled from years of literally basement recordings - it was very easy to dismiss them as songs from a once-great forced to wile away his time in a critical Siberia. But upon closer inspection, these deceptively slight tunes begin to carry a deeper relevance.

In fact, they do nothing short of evoking the very thing that Replacement worshipers used to gaga over. Indeed, the new albums are Westerberg not giving a fuck in high style while retaining an exceptionally high level of quality.

As with much of his solo career, Stereo/Mono has been hampered by incorrect assumptions and assessments. The Stereo disc is an introspective, acoustic-heavy affair - this means it's a supposedly more insightful and significant artistic statement. Mono - recorded under the goofy alter ego moniker of Grandpaboy - is all rocks-out bravado and has been slagged for its one-dimensional attack. (And, therefore, Mono must be Westerberg's half-hearted stab at regaining his Replacements youth, right?)

Over time, though, the albums don't play out that way. They're each better than advertised and yet they both lack something individually that the other disc compensates for wonderfully.

Stereo is a collection of terrific songs about Westerberg's happy struggles with adulthood. He still writes tunes about girls, but they don't have the scary, freshly-drawn pain of earlier gems like "Answering Machine" or "First Glimmer." Now, they center on more mature worries, like commitment, remaining sane, and holding on for the long term. Children and aging are nasty little jokes at the expense of grownups on Stereo - grownups who tell themselves that they aren't old, but who aren't quite sure exactly.

And even if Westerberg is becoming a fogey, tunes like "Boring Enormous" and "We May Be the Ones" - decked out in all their unplugged glory - don't have a lick of resigned complacency to them. Westerberg made a big deal about these songs' off-the-cuff recording method, and for once that description doesn't sound like laziness disguised as authenticity. There's nothing smug or forced in Stereo's ballads. They emerge as their creator intended: unrushed, personal, unaware of a songwriter's mythic legacy. And, oddly enough, this relaxed material is some of the strongest, most affecting work of his career. There's a confidence and intimacy in these songs. They feel almost blasé and still they resonate.

With all that said, Stereo only tells half of the Westerberg story - and that's where Mono comes in. Far from being dull or someone's idea of a nostalgia trip, the rock disc fills in the blanks of the acoustic disc. Where Stereo accepts turning 40, having no record label beating down your door, and running out of money, Mono bracingly says to hell with it all. After the measured honesty of Stereo, Mono's Stones/Who exuberant catharsis feels like a relief. (Tellingly, one of the best lyrics on Mono goes something like "Papa papa coppa/Papa papa coppa" and who cares what he's really saying?)

Quite clearly, what becomes apparent about Mono is just how joyously loud and immaterial it feels. Westerberg has inspired a series of songwriters, all who have gone on to much bigger success than he's ever known. (You can't listen to Nirvana, the Goo Goo Dolls, or Ryan Adams without hearing the Westerberg imprint.) But what Mono should remind the faithful is that it wasn't just a sound that he conjured up so remarkably - it was a feeling. Too often, that feeling - youthful exuberance without discipline or direction - has been equated with the Replacements' disheveled live shows and attitude. (While the Goo Goos just ripped off his balladeer ability, Kurt Cobain and Adams responded to that no-rules anarchy.) But Mono doesn't spare a moment or get off on sloppiness. Westerberg's done that to death already, and he knows it. Instead, these corkers are tight and focused, and they turn out to be much more stirring than you might think at first.

And they've got a great mean streak to 'em, too. "Silent Film Star" is a snotty little kiss-off to one of a thousand superficial prima donnas. Later, "Eyes Like Sparks" tries to untangle a sexually explosive relationship that most certainly is bad for you - but one you can't quite let go. Westerberg has always walked the line of being a well-meaning misogynist simply because he's pretty vicious when she walks out that door. But age has mellowed him, lending him some compassion to go along with his biting wit. Mono is full of bad lovers, but there's very little permanent damage. The rock disc allows him to go home again without denying that he may not fully recognize the place anymore.

Contrary to the naysayers, marriage, a child, and sobriety haven't deadened him; rather, they've rid him of the spiteful pettiness that's marred a lot of his post-'Mats records. Before, he sometimes seemed infuriated that his relevance had shrunk, that he would only be remembered for the Replacements. The trick to his newfound spark was simply going away - escaping from view, giving up on the music business, and then eventually going down to the basement to finally write some songs.

The triumph of Stereo/Mono is that by dropping off the face of the earth - by becoming as irreverent as his critics said he had become - Paul Westerberg was able to find himself again. Taken together, not only are these albums the best double-disc work in quite some time by anybody, they're also one of his greatest works.

I'm just sorry it took me so damn long to figure it out.

Tim Grierson is an editor of The Simon, a weekly online publication of culture, politics, and humor, found at www.thesimon.com.