NEW YORK (Reuters) - Some of the world's biggest names in music including Beyonce, Cold Play's Chris Martin and Rihanna are backing Jay Z's new global streaming music service Tidal, which launched on Monday, and is billing itself as the first of its kind owned by artists.

Co-owners Kanye West, Daft Punk, Alicia Keys, Madonna and other musicians were in New York on Monday to sign a declaration of a "whole new era."

Still, Tidal is entering a crowded space, with stiff competition from Spotify, Pandora Media Inc and Clear Channel's I Heart Radio.

But Jay Z's deep music ties could help distinguish Tidal from its rivals.

Musicians complain they are not being properly compensated for digital music rights. Additionally, music downloads have been shrinking as streaming services boom in popularity.

The Beatles' Ringo Starr addressed the issue with Reuters TV on Monday: "All I ever hear is that your record has been streamed 17 million times and they give you a cheque for 12 bucks. I don't understand that."

Last year, Taylor Swift pulled her entire catalogue from Spotify in a shocking move.

Swift's catalogue is available on Tidal but her latest 1989 is not.

Tidal has deals for rights with all the major record labels, a representative with the company said.

While the glitzy line-up on Monday did not directly address compensation, Alicia Keys said, "We believe it's in everyone's interest... to preserve music."

Tidal is offering a mix of stock and cash to its owners for promotional support, which does not include rights to the music, the Financial Times reported.

One partner was offered US$3 million for a 3 per cent stake, the report said.

Tidal is an offspring of Jay Z's company Project Panther Bidco, which acquired more than 90 per cent of the Swedish streaming music company Aspiro AB for US$54 million earlier this month.

For US$19.99 a month, subscribers have access to millions of songs and videos in high fidelity.

A US$9.99 option offers regular sound quality. Tidal is available in 35 countries and subscribers can listen offline to as many songs as their device will hold.