You know that the millennium is at hand when Paul McCartney, seemingly the most light-hearted of the Beatles, re-records some of his old songs as orchestral pieces for a new album titled ‘Working Classical.’

From McCartney’s classical excursions to new, often quite serious, millennium-themed pop songs, the next few months promise to bring a rare spectacle: rock stars attempting to become more weighty and grave in accordance with the end of the century.

McCartney has tackled the issue two different ways; besides ‘Working Classical’ he has come out with another album for EMI records – the rocking ‘Run Devil Run.’ This offers new versions of old rock standards like ‘Lonesome Town’ and ‘Brown Eyed Handsome Man.’

Both albums are now selling in the United States and, of the two, ‘Working Classical’ – recorded with the London Symphony Orchestra and the Loma Mar Qintet – is the more interesting effort.

It features some of the most frivolous tunes of McCartney’s solo career and tenure with the rock band ‘Wings’ and turns them into whimsical pieces of chamber music.

Most classical remakes of rock songs suffer from sounding a bit too much like goofy summertime pop hits – especially several tunes written for McCartney’s late wife, Linda, such as ‘The Lovely Linda,’ ‘My Love’ and ‘Maybe I’m Amazed.’

Still, hearing the electric guitars and keyboards of the original versions turned into cellos and violins has its own charm.

Even better, new compositions like ‘Junk’ and ‘A Leaf’ are genuinely beautiful, fragile works that update the semi-orchestral sound the Beatles used to good effect on ‘Sgt. Pepper’s Lonely Hearts Club Band.’

On the whole, ‘Working Classical’ suggests that McCartney could have a future in classical music if he sticks to his gifts for attractive, ethereally light melodies.

His forte clearly is the sort of miniatures and chamber pieces on this album, rather than the overblown symphonic works – such as ‘The Liverpool Oratorio’ and ‘Standing Stone’ – which he has written in recent years.

On the other hand, ‘Run Devil Run’ – which McCartney told one magazine he had recorded so he could end the millennium with rock and roll – shows that 1950s rock sounds just as dated now as any classical music!

Although McCartney sings with flair and plays bass with abandon, his band – including Pink Floyd guitarist David Gilmour – plods through some relatively pleasant songs associated with Chuck Berry, Elvis Presley and other rock icons.

Both McCartney’s records display an attitude of trying to grasp for some meaning – the enduring quality of rock and roll, the connection between popular and classical music – at the century’s end.

Other pop stars – notably Sting, formerly of the rock group, ‘Police’ – are even more explicitly millennial in their ambitions. Sting’s new album ‘Brand New Day’ (on A and M) opens with a sombre song about the last millennium, ‘A Thousand Years,’ and closes with a more upbeat tune, ‘Brand New Day.’

The latter is a fun, cock-eyed bit of optimism, looking forward to the Y2K computer virus as the day that all the machines will run down – and afford humans an opportunity to start anew.

With some joyous harmonica playing by Stevie Wonder and Sting in an uncharacteristically jaunty mood, ‘Brand New Day’ offers one of the most peculiar cases for celebrating the year 2000 that has been heard so far.

Nevertheless, one can assume that the next few months will bring even more pop stars to consider millennial topics. Already, rapper Will Smith has come out with a new song, ‘Will2K,’ in which – with typically good-natured arrogance – the rapper dubs the next thousand years after himself as the “Willennium.”

Even at the year’s beginning, British pop star Robbie Williams scored a hit with Millennium, which employs theme music from a James Bond film as it rhymes “we have stars against our fate” with “we’ve already fallen from grace.” And rapper Wyclef Jean and U2 singer Bono have collaborated on another millennium-themed song, which they played at last month’s NetAid concert.

So, is popular music set to take on weightier issues – or is the millennium just a fad for the next few months?

The best answer probably can be found with the Backstreet Boys, who titled their latest album ‘Millennium’ – presumably because it sounds like a sufficiently grandiose concept for an album title.