The Official UK Charts are entering a new era as of 1 January, as the music industry recognises the digital revolution.

Downloads have helped to double the size of the UK singles market in 3 years, from 32.3 million tracks sold in 2004, to 65.1 million in 2006.

Two major rules have been changed. From 1 January, record labels won't be required to make physical single available, so that any legally available download will be eligible for the Official Singles Chart.

Last March, downloads were allowed to be released and considered for the chart one week before physical albums went on sale; the result meant that Gnarls Barkley's Crazy became the UK's first download-only number one track.

In order to ensure that sales of physical EPs don't suffer, the Official UK Charts Company has also ruled that each EP can contain up to four tracks lasting a total of 25 minutes. Previously, only three tracks totalling 20 minutes were accepted.

The BPI shows that downloads are outselling physical single sales, accounting for 80% of the total single market by December 2006, 66% of the total singles chart market, and 52% of the Top 4-singles chart market.