It adds to other sharing functions on the site including the ability to send email links and post music in blogs.
We7 lets users listen to music online for free, with advertising funding the cost of listening. Advertisers can target ads at users based on the information that they supply when signing up, although the site can still be used without joining.
Unlike rival free music services, it also allows people to buy music directly from an in-site store. It encourages users to share their favourite songs with others by creating playlists.
With just over 1,000 followers on Twitter, We7 lags behind Spotify, which also lets users listen to music for free and create playlists, with 8,300 followers.
However, Steve Purdham, chief executive and founder investor in We7, said that the company was less worried about user numbers and that the instant sharing capability in We7 -- unlike Spotify where users must download a dedicated player -- would pay off.
"Consumers love getting the music they want and artists love getting paid for it," Purdham said.
Investors in We7 include Peter Gabriel, one of the founders of the band Genesis.