Apple has launched a social network as part of the latest version of its iTunes software.

苹果发布一个社交网络作为其最新iTunes软件的一部分。

Ping, as it is known, allows users to build networks of friends and professional musicians, in a similar way to services such as Twitter.

The service also builds playlists based on what friends are listening to.

Analysts said it represents a challenge to existing music-based social networks such as MySpace.

"It's a social network all about music," said Mr Jobs, launching the application at an event in San Francisco.

"We think this will be really popular very fast because 160 million people can switch it on today," he said.

The service will be accessible through iTunes 10 software on Macs and PCs as well as through the iTunes application on iPhones and the iPod Touch.

Network killer?

Analysts at research firm CCS Insight said it represented an "ambitious move" that would present a challenge to "ailing（生病的，体衰的） MySpace and other social networks".

Michael Gartenberg, partner with research firm Altimeter group, agreed.

"MySpace is the one that has to look at what this means to them and will probably face the greatest competition from Ping in the short term," he told BBC News.

"They are going to have to figure out a way to differentiate themselves because Apple is already where I am buying my music and this is a natural extension. You wonder why the music industry collectively hasn't thought of this before."

MySpace has traditionally attracted musicians, who use the site to share their own music and discover other artists. However, its growth has stagnated（停滞） .

"Ping destroys whatever was left of MySpace's market share," said Xeni Jardin, co editor of the technology blog Boing Boing. "It remains to be seen what kind of competition it poses for Facebook."

But Apple co-founder Steve Wozniak told BBC News that Ping was not about taking audiences away from other networks.

"It sounds like a subset（子集，小团体） of Facebook, but Facebook is life and this is music."

Mr Jobs billed it as a new way to discover music.

The service allows users to create their own profile on iTunes, which details friends lists, what music they are listening to and which concerts they will attend.

It will also show a top 10 list of songs and albums their friends and the artists they follow are downloading from iTunes.

Some features of Ping already exist in services such as Spotify and Last.fm.

However, iTunes is currently the largest online music service.

Mr Jobs said that since launch, nearly 12 billion music tracks had been downloaded from the site.