Christina Aguilera, the schoolgirl star, performed on a new platform last weekend. InterTrust Technologies, the Californian information technology group, launched its digital rights management system for public viewing at a global gathering of the music industry in Cannes.

The rendition of Love for All Seasons was accessed through CD-Rom or downloaded from the Internet, using the encoding and encryption technologies that have made the US company almost as much of a hit with new media investors as the youthful Ms Aguilera is with pop fans.

The public trial of the new technologies is part of a broader challenge which is consuming the world music industry; selling music over the Internet.

The multi-billion-dollar merger announced this week between British music group EMI and US media giant Time Warner is a manifestation of this, with the new global giant intent on exploiting the use of the Internet to download music. The tie-up will be a leading source of music content for the Internet, linking EMI to the world's largest Internetmedia group which Time Warner plans to form with online outfit AOL.

The established music business was initially unnerved by the development of digital technologies - particularly the MP3 format for downloading music over the Internet - and its potential to ease piracy, erode the status of the record label and break down the relationship between artists and music companies. But the industry has begun to move on.

At the annual Midem get-together of the music business, the industry bosses and the new media netpreneurs, considered how they could harness the value of the rapid growth in the online music market.

The projections for online music sales explain the industry's determination to get onboard. Sales of music over the Internet including both online retailing of CDs, tapes and records, as well as digital downloads, are forecast to grow from $152 million (€151.58 million) in 1998, or 1.1 per cent of the total US market, to $2.6 billion, or 14 per cent of the US music market, in 2003, according to Jupiter Communications, the market research company.

The bulk of this, though, will be "old-fashioned" online retailing - digital demand to Internet music retailers, backed up by "snail-mail" delivery of hard copy CDs.

Digital downloading of music - which threatens to cut out the hard copy industry altogether - will only take off in the longer term, according to Jupiter. It suggests that digital distribution revenues in 1998 were "effectively nil", and only expects digital distributors to be earning $147 million by 2003.

To judge from the rash of new deals and product launches, though, digital delivery is already firing the imagination of the music industry.

Alongside Ms Aguilera's performance, delivered by Universal Music Group in conjunction with InterTrust, there were many other acts appearing courtesy of a range of new digital techologies.

In addition, the Backstreet Boys, the boyband sensation, announced last week that they will be airing one of their US concerts over the Internet. MCY.com, the New York-based digital retailer and sponsor of the Boys' "Into the Millennium" tour, will air a pay-per-view webcast of one of their US college fixtures.

RealNetworks, one of the leading businesses in media delivery on the Internet, agreed a deal last week to integrate technologies from BackWeb Technologies, a Nasdaq-listed company.

The agreement gives a technological backbone to RealJukebox, an Internet music site that allows consumers to receive songs and samples online.

The deal is one of a number aimed at digital delivery, evidence of the growing enthusiasm of dial-and-download technologies in the music industry. But there looks as though there will be a lag between what consumers can do and what they will do.

For the next few years, the hardware needed to exploit the opportunities for digital download will remain uncommon. Estimates suggest that there were 500,000 installed digital playback devices at the end of last year, and that this number will only grow to about five million over the next four years.

There is also the same cultural obstacle to piping music to the consumer via the PC that could dog the development of visual entertainment and information over the Internet.

Many believe people will continue to segment their working lives, where they keep their computers, and their leisure space, where they house a television and a music centre.

The consumer electronics manufacturers are beginning to blur the lines, but the single combined entertainment, information and communications console is still judged to be several years out.

Established music companies also know they face fundamental adjustments to their business habits.

Dealing with Internet delivery will change the relationship between the manager of talent and the consumer market, giving companies more knowledge than they ever had about the consumer.

But, as bands from the Beastie Boys to Oasis have shown by testing the patience of their record labels, the Internet gives artists greater freedom, too. Digital delivery will weaken the music bosses' control over the artist - even school-girl stars like Aguilera.