Sony has launched its biggest challenge yet to Apple's digital music dominance, unveiling five players and a jukebox software application that ties into its online music store.

The range includes three flash-memory-based models with capacities of 512MB, 1GB and 2GB, and two hard-disk drive-based models with capacities of 6GB and 20GB. They will be available in Japan from October. International launch plans have not yet been set.

Sony created the portable audio category with its Walkman cassette player 22 years ago, but in the digital music player market it has lagged behind Apple and other companies for a few years.

Sony on catch-up while Apple changes the game

The new players closely mimic Apple's in terms of capacity and the type of storage used - or at least, they would have had Apple not killed off it's 1-inch hard-disk drive-based iPod mini a few hours prior to Sony's announcement. Apple launched its new flash-memory-based player called the iPod nano last night. It will replace the iPod mini and be available in 2GB and 4GB capacities.

Sony is emphasizing the user interface of the new players rather than just the technical specifications. Among the functions on the hard-disk drive-based models is an "artist link." Clicking the link button while a song is playing highlights stored music from similar musicians and genres. There are also several shuffle modes in all the players, including a "time shuffle," which will play all the stored songs from a selected year, and a mode that randomly plays songs from the top-100 most listened-to tracks.

The same artist link function is available in Sony's new jukebox software. Called "Connect Player," the software interface bears more than a passing resemblance to Apple's iTunes software and has many of the same functions. It can also be used to access the Mora online music store established by Sony and many other record companies for the Japanese domestic market.

To promote the service Sony will begin selling pre-paid music cards in ¥1,000, ¥2,500 and ¥5,000 denominations.

Sony’s aim to claim the music

But perhaps the strongest indication that Sony has Apple in its sights came with the endorsements offered by music company executives at the Tokyo news conference on Thursday. Joining Sony Music on stage to offer support for the new players were top executives from Avex Network and Toshiba-EMI, both of whom were among the initial supporters of the iTunes Music Store Japan that opened last month.

The new players have several technical features in common, such as an OLED (organic light emitting diode) display. The display sits under a face plate and so is only visible when the player is switched on and the display lights up. Music file support extends to MP3 and Sony's ATRAC formats, and Sony is looking at adding Windows Media Audio and AAC support in future players, it said Thursday.

The three flash-memory based models have an FM radio and offer up to 50 hours of playback time. Sony said it hadn't worked out the battery life yet for the hard-disk models.

The smallest capacity flash model, the 512MB NW-A605, will cost ¥22,000; the 1GB NW-A607 will cost ¥27,000; the 2GB NW-A608 will cost ¥32,000; the 6GB NW-A1000 will cost ¥30,000 and the 20GB NW-A3000 will cost ¥35,000, Sony said.

In contrast, Apple's 2GB model costs $199 (¥21,900).