If you still think Paul McCartney is that guy who wants to fill the world with silly love songs, you haven't been paying attention.

Of course, you're hardly alone in that. Few people beyond the faithful seem to have noticed that for most of the past decade, the former Beatle has been quietly but deliberately engineering an impressive artistic rejuvenation.

On discs like 1997's Flaming Pie and 2001's Driving Rain, he moved past the superficial pop he's become known for and began to delve into darker, deeper, more personal terrain. He wrote about the death of wife Linda and his subsequent despair. He wrote about the emotional rebirth brought by new love Heather Mills. He even made forays into electronica, orchestral and chamber music. In short, he challenged himself instead of resting on his admittedly considerable laurels. And it has led to some of the more revealing and intriguing work of his solo career.

What it all seems to have been leading up to, however, is Chaos and Creation in the Backyard, his 20th post-Beatles album and his most ambitious, accomplished and artful disc in decades. Once again, it seems to be the product of McCartney's refusal to take the easy road. Instead of producing himself, he brought in the respected maverick Nigel Godrich, famed for his groundbreaking work with Radiohead and Beck.

Instead of knocking out tunes with the mates in his touring band, he capitulated to Godrich's wishes and played nearly all the instruments himself, reconnecting with the one-man band ethic of his DIY albums McCartney and McCartney II. Instead of sunny commercial pop and driving rock, he aims for a sombre, serious and sophisticated tone.

Most importantly: Instead of trying to escape the sound of the Fabs, he embraces it, turning Chaos and Creation into a disc with a career-spanning resonance. Opener Fine Line bounces along to a piano line that reminds you a little of Lady Madonna. Jenny Wren is a folksy ballad akin to Blackbird. English Tea channels the twee whimsy of Maxwell's Silver Hammer -- with the fluty solo from Fool on the Hill making a cameo.

Riding to Vanity Fair borrows the strings from Eleanor Rigby. Promise to You Girl hints at the "Life is very short" refrain from We Can Work it Out. If anybody else did it, you'd accuse them of blatant Beatlemania; when McCartney does it, well, it's pretty tough to slam a guy for being influenced by himself. Though to be fair, it's not as if the whole disc is a Beatles revamp. One cut, glides to a light Latin groove. Another has echoes of Curtis Mayfield's People Get Ready.

And there's plenty of contemporary yang to all this nostalgic yin, supplied mainly by Godrich. He is arguably the most gifted and daring producer to work with McCartney since George Martin. He's certainly the only one who's managed to put his own stamp on the man's work. Augmenting McCartney's warm, hummable melodies with his trademark chilly textures and woozy ambience, Godrich both expands McCartney's sound and drags it into this millennium. Granted, it's a long way from Kid A, but for McCartney, it's still fairly edgy stuff.

Despite all this coherence, cohesion and creativity, Chaos and Creation in the Backyard is not without its faults. Most are in the lyric department. While McCartney has grown more reflective and revealing over time, his poetic skills haven't improved much. Basically, he's still a moon-June-spoon rhymer ("I thought there couldn't be / A someone who was there for me;" "Sometimes I'd rather run and hide / Than stay and face the fear inside") who remains fixated on romance. And he's still eminently capable of writing the occasional silly love song.

Even so, when a guy who's been making records for four decades can up the ante the way McCartney does here, it's worth paying attention.

Track Listing:

1. Fine Line
2. How Kind of You
3. Jenny Wren
4. At the Mercy
5. Friends to Go
6. English Tea
7. Too Much Rain
8. Certain Softness
9. Riding to Vanity Fair
10. Follow Me
11. Promise to You Girl
12. This Never Happened Before
13. Anyway