Chart rules are changing!

The Top 40 singles are compiled in a new way since Sunday 7 January.

Singles can now chart from the moment they become available as official downloads.

Check out how the all new Top 40 looks now!

That could be four or five weeks before the CD comes out. Before Sunday, downloads could only chart one week before the CD release.

Downloads are no longer affected when the CD is deleted. As long as it's available as a download, it's eligible.

So under the new rules, Snow Patrol's Chasing Cars would have spent the last couple of months in the Top 20.

Under the old rules it wasn't chart eligible because the CD had been deleted.

Tracks available as individual downloads from albums and EPs can also enter the singles chart - so tracks from the recent Oasis EP could have charted under the new rules.

Old tracks available as downloads can also chart. Such as Aerosmith's I Don't Want To Miss A Thing - it was recently performed on X-Factor and enough people then downloaded the original to get it in the chart.

Under the old rules it wasn't eligible, under the new rules it is.