IF, IN February 2000, you still don't believe that modern rock is on borrowed time as an art form, despite all the overwhelming evidence, then consider this. It has fallen to two men in their mid-50s, men who look like The Chemical Brothers after a decade in a South American dungeon, to make what is surely the rock record of the year. How sad is that?

Unsurprisingly, given the time-gap involved, Two Against Nature finds Donald Fagen and Becker moving even further away from the relatively simplistic material on their first three albums, and up to the extraordinary level of melodic refinement that reached its apotheosis on their last studio album, 1980's Gaucho.

The production is as crisp and clear as a spring morning. Like all great drenched-in-detail albums, you could listen to Two Against Nature 50 times on the trot and still hear little touches and aural squiggles you hadn't picked up before: the sheer attention to detail on Two Against Nature is quite extraordinary. Each horn arrangement, each immaculately worked-out guitar solo, each perfectly executed drum-fill is so spot-on that it defies belief.

Fagen's voice, hollowed out and made extra-nasal by years of coke abuse in the 1970s and 1980s (though he's now been clean for ages), is as good as the instrumentation. His vocal phrasing is as immaculate as ever: on 'Janie Runaway', an

affectionate swipe at early-morning radio DJs, he blends his reedy tones perfectly with the saccharine doo-wop crooning of the backing vox.

Predictably, they haven't passed up the opportunities to revisit old ground. Fagen's perennial fascination with Hollyweird gets another airing on 'What A Shame About Me'. Musically, it's one of the gentler songs on the album, though with a chorus that you'll tie yourself in knots trying to follow. Lyrically, it's as droll as you'd anticipate. Similarly, the slinky, spring-loaded coil of 'Cousin Dupree' (Fagen lecherously drooling over a sexy relative) is effectively a sequel to the younger-woman fantasy of 1980's 'Hey Nineteen'.

The languid, unhurried jazz-blues of 'Jack Of Speed' sees Becker's graceful guitar take centre-stage, leading the vocal melody along by the nose. On the opener, 'Gaslighting Abbie', they get as close to black funk as they ever will; on the beautiful 'Negative Girl' (which should have closed the album), they stretch themselves even further than usual, hurtling through about seven key changes in five seconds.

I honestly didn't think they had it in them, this late in the day. Nobody did. But believe me, the boys have delivered in style. Two Against Nature is so good, so melodically delicious, so luxuriant that anybody who delivers a better album this year will mess with your perceptions of music as surely as this has messed with mine.

Absolutely astonishing.