They had massive hits last year, but now Snow Patrol and Gnarls Barkley are soaring up the charts again - with their old songs.

They have benefited from a dramatic change to the Top 40 rules introduced last week which means any old favourite can hit No.1 again.

In the biggest shake-up to the charts since 1952, any song available as an Internet download is now eligible for the charts, regardless of when it was released.

Thus Snow Patrol's Chasing Cars, released last July, has returned as this week's No.9.

And Crazy, by Gnarls Barkley, the biggest hit of last year, is now at No.30.

Mad World, the 2003 Christmas No.1 from the Donny Darko soundtrack, was tipped to make a return but failed.

Until now, songs were removed from the chart two weeks after the physical copy of the single was deleted.

HMV spokesman Gennaro Castaldo said: 'Under the new rules, anything and everything is eligible.

'The charts will now offer a much broader representation of the nation's music tastes.

'January is always the quietest-month for singles sales so older songs are benefiting.

'But old releases are likely to feature heavily now.'

The shake-up also raises the possibility of The Beatles staging an almighty comeback.

There are rumours that EMI is negotiating to release the band's back catalogue as downloads for the first time.

Mr Castaldo said: 'If The Beatles' songs were made available digitally, a top ten made up entirely of their music would be almost guaranteed.'

Despite the changes, X Factor winner Leona Lewis remained at No.1 with A Moment Like This.