KEY POINTS:
The singles chart, once an essential fixture in every teenage life, is poised to undergo one of the most significant transformations in its 40-year history.
From tuesday, chart position will no longer be pegged to the existence of a physical product in the form of a CD single or seven-inch vinyl release.
Instead, digital downloads, which outstripped physical sales for the first time earlier this year, will dictate the risers and fallers in the Top 40. This means that any song available on the internet - including "golden oldies" - could top the charts.
Experts said that old tracks revived for television advertising campaigns and films but not re-released could well appear in the charts again - such as the post-punk soundtrack to the Sofia Coppola movie Marie Antoinette which included New Order, Siouxsie and the Banshees and The Cure.
The aim is to make the charts more representative of what consumers are actually buying and re-inject a sense of excitement into an institution that was looking past its sell-by date after years of declining single sales.
While downloads have been included in the chart make up since 2005, they have only been counted if there was also a physical product.
But the success of artists like Gnarls Barkley, Lily Allen and the Arctic Monkeys, who built chart success on the back of their internet popularity, has convinced the Official UK Charts Company (OCC) to act.
From Tuesday, all download sales will count - including album tracks and even old numbers given a new lease of life by use in advertising or a film. It should mean the charts are less dominated by the tastes of teenage girls.
Steve Redmond, the OCC's director, described it as a dramatic development in the history of the official charts.
"For the past 54 years, a single was a track selected by a record company to be pressed on plastic and distributed to stores on a particular date.
"From now on, a single can be any track currently available as a download - even an album track or a golden oldie - as well, of course, as the established physical formats of CD, DVD, seven and 12-inch vinyl."
The new ruling changed the nature of a single and put the consumer in the driving seat, he said.
"Literally any track can be a hit - as long as it sells enough."
The bid to boost the market comes after a turbulent few years for the music industry.
From the 1970s until the end of the century, sales remained relatively static at around 70m, with new movements generating such as punk and Britpop generating their own excitement and sales spikes.
But the singles market went into free-fall at the end of the century. Between 1999 and 2004, it crashed to around half the total of its heyday, because of illegal downloading and filesharing sites.
The industry fought back, offering a range of new, legal and paid-for digital services. As a consequence, legal downloads have risen from 5.8m in 2004 to 50m in 2006, accounting for 60 per cent of the overall market and 80 per cent of back catalogue sales, although the decline in physical sales looks set to continue.
Gennaro Castaldo, of the record store HMV, said they believed that every track should be accessible to customers. But they feared that the shift to downloads would mean some singles would not be available and some labels might want to phase out physical sales altogether.
However, the resurgence of the seven-inch market, up to 2m this year, showed there was demand.
"One reason we don't believe that physical sales will disappear is because enthusiasts continue to want to own a single or album."
Steve Kincaid, of Virgin Megastores, said they believed the changes were "a positive move forward, as they clearly reflect consumers' buying habits".
It was important that the charts moved with the times. But he said: "There is still an incredible demand for a physical single when the right artist comes along. Leona's X Factor single is the most obvious and recent example of this, but there have been others throughout the year and it is important that the physical market is catered for."
- INDEPENDENT