Musicians unite behind Jay Z streaming service
Musicians including Kanye West, Jack White, Rihanna, Madonna and Coldplay are uniting behind Jay Z's "artist-friendly" streaming site, Tidal.
They all turned their Twitter profiles teal blue, to reflect Tidal's branding, on Sunday night.
The site launches on Monday, promising CD-quality streaming and thousands of music videos, for a subscription fee.
Taylor Swift, who pulled her catalogue off Spotify last November, is among those to feature on the service.
Her back catalogue - with the exception of her current album, 1989 - is already available on the service, which requires a monthly subscription of $9,99 (£6.72) for standard-quality music, and $19.99 (£13.47) for the "high fidelity" option.
A spokesperson for Swift said that the star's back catalogue appears on all streaming services that require a subscription fee.
"This has never been changed. Big Machine Records believes music has value and we do not believe Taylor's music should be made available for free," they said.
Other artists publically backing Tidal on social media included DJ Calvin Harris, R&B star Usher, country singer Jason Aldean and Beyonce, who is married to Jay Z.
It has also been rumoured that Rihanna's much-anticipated eighth album will premiere on the service after Monday's launch event.
The R&B singer is signed to Jay Z's Roc Nation label, making such a deal possible, but there has been no official confirmation.
Jay Z's company Project Panther bought Aspiro, a Swedish tech firm that runs two streaming music services (WiMP and Tidal) for $56 million (£37.7m) on 13 March.
According to Forbes, the rapper intends to allow artists who sign up to his site reap more rewards than they would on rivals such as Spotify, Rdio, Rhapsody and Beats Music.
He will announce his plans at a live-streamed launch event at 22:00 GMT in New York.
A press invitation for the event promised that "Shawn 'Jay Z' Carter and special guests will announce a commitment to a new direction for the music industry from both a creative and business perspective".
The launch comes as the streaming market becomes increasingly competitive.
The rapid success of Spotify, which now has more than 15 million paid subscribers and 60 million total users, has prompted many tech companies to launch similar services.
Last year, Google announced a subscription service that allows users to stream ad-free music videos, and download them for offline use.
The monthly fee for Music Key also provides membership to Google Play All Access, the firm's pre-existing "all-you-can-eat" music facility.
And Apple is poised to launch its own service, after paying $3bn (£2.02bn) for headphone maker and music-streaming provider Beats Electronics last year.
It recently poached Radio 1 DJ Zane Lowe for an undisclosed role in its music division.