Currently in the public beta phase, Amazon's "MP3 Store" wants to be the biggest collection of DRM-free music on the Web, with over 2 million songs from more than 180,000 artists.

More than 20,000 major and independent record labels are included in Amazon's list, which is complementary to the Internet giant's "solid state" offering, that surpasses 1 million CDs.

"This new digital music service has already been through an extensive private beta," said Amazon.com vice president for digital music Bill Carr.

"Today we're excited to offer it to our customers as a fully functional public beta."

"Amazon MP3 is an all-MP3, DRM-free catalog of a la carte music from major labels and independent labels, playable on any device, in high-quality audio, at low prices," Carr added. "This new digital music service has already been through an extensive private beta, and today we're excited to offer it to our customers as a fully functional public beta. We look forward to receiving feedback from our customers and using their input to refine the service."

Amazon's clear aim is to attract unsatisfied customers from Apple's iTunes, currently the third largest music retailer in the US and the most powerful music download service on the Web. Despite Apple's clear dominance in the digital music industry, the presence of DRM software in almost every song sold through the online store is keeping a lot of potential customers away and it definitely frustrates others, who have to buy an iPod and only an iPod to be able to listen their favorite songs.

Amazon exploits this weakness of iTunes by underlining that every song or album on its MP3 Store is sold in this unprotected format, thus making downloaded tracks compatible with all MP3 players currently on sale, including Apple's iPod and iPhone, Microsoft's Zune, Creative's Zen, SanDisk's Sansa or Toshiba's GigaBeat. Of course, MP3-enabled phones along with PCs and Macs will also be able to play Amazon's content without restrictions.

Jeff Bezos' site says more than half of its catalogue (1 million songs) will be priced at 89 cents, making the offer even more interesting for potential buyers, because iTunes sells tracks for 10 cents more. Moreover, the top 100 best-selling songs are 89 cents, unless marked otherwise, while the top 100 best-selling albums will cost you $8.99 or less, unless marked otherwise. Most albums will be priced from $5.99 to $9.99. If what Amazon is saying about MP3 Store is true then the online service's debut is pretty impressive, considering for example that Zune Marketplace has the same number of tracks, but after almost a year on the market.

Every song on Amazon MP3 is encoded at 256 kilobits per second, which gives customers high audio quality at a manageable file size. Amazon tried to make things as easy and comfortable as possible with its Amazon 1-Click shopping, while the Amazon MP3 Downloader helps clients integrate their MP3s into iTunes' or Windows Media Player's libraries.

Amazon MP3 has over 2 million songs from more than 180,000 artists spanning every genre of music, including 50 Cent, Alison Krauss, Amy Winehouse, Ani DiFranco, Arcade Fire, Beastie Boys, Coldplay, Creedence Clearwater Revival, Ella Fitzgerald, Feist, John Coltrane, KT Tunstall, Keith Urban, Koko Taylor, Lily Allen, Madeleine Peyroux, Maroon 5, Marvin Gaye, Miles Davis, Morrissey, Nelly, Nickel Creek, Nirvana, Norah Jones, Paul McCartney, Philip Glass, Pink Floyd, Pixies, Radiohead, Ray Charles, Rod Stewart, Spoon, Stevie Wonder, The Chemical Brothers, The Decemberists, and The Rolling Stones.

"Well done Amazon for making so much music available to so many people," said KT Tunstall. "It's good to know, in the words of The King, you're taking care of business!"

Leading independent labels offering their catalog of music for the first time as DRM-free MP3s include Alligator Records, HighTone Records, Madacy Entertainment, Sanctuary Records, Rounder Records, Righteous Babe Records, Sugar Hill Records, and Trojan Records.