The battle over how music will be distributed online saw Napster, record bosses and stars meet with US lawmakers yesterday, while MSN said it would today launch its own service, MSN Music.

Napster executives, singer Alanis Morissette and Recording Industry of Association of America (RIAA) chief executive Hilary Rosen all testified before a Senate committee at a hearing called 'Online Entertainment and Copyright Law: Coming Soon to a Digital Device Near You'.

Morissette, an alternative rock artist best known for her CD Jagged Little Pill, appeared to support a legalised version of Napster.

She told the hearing that artists had developed different opinions from those of their record labels but feared a backlash should they speak out. She said: "History has not been kind to artists who have candidly expressed points of view that differ with those of their record company.

"My initial resistance to the new services created online was based on the debate having been framed in terms of 'piracy'... but what I have since come to realise is that for the majority of artists, this so-called 'piracy' may actually have been working in their favour."

She added: "History has proven time and again that a greater variety of formats and distribution opportunities lead to more choices for consumers, increased awareness of the artists and their music, and ultimately a continued and greater reward financially, creatively and personally for everybody involved."

Napster meanwhile called on the Senate to legislate on digital distribution to prevent a "decade of litigation". Hank Barry, chief executive at Napster, said that independent experts had begun to examine its filtering service to establish whether it complied with an injunction granted to the RIAA.

Hilary Rosen, chief executive at the RIAA, dismissed Napster as old news.

She said: "Napster was exciting. But giving away someone else's music without their permission is yesterday's news. The story now is the music industry's efforts to alert fans and consumers to the huge amounts of legitimately licensed music that is currently available online."

Earlier this week, music giants EMI Group, Bertelsmann and AOL Time Warner together with RealNetworks launched their own rival to Napster in the shape of MusicNet, an online music subscription service.

Now, Microsoft has entered the fray with today's launch of MSN Music, which offers thousands of radio stations online combined with search technology. However, users cannot request songs on demand, only radio stations that play the chosen artist.

US analysts have dismissed the launch as more of a statement of intent that Microsoft will be a player in online music distribution in the future, rather than a major innovation.