As a superstar artist and influential executive through his company Roc Nation, Jay Z has unusual power in the music industry. He is said to be courting new artists aggressively to join the service and offer Tidal special material and “windows,” or limited periods of exclusive availability.

Yet Jay Z is entering the streaming fray as a boutique competitor against some of the most powerful companies in the business. Spotify has 60 million users around the world, 15 million of whom pay; Apple is expected to introduce a subscription streaming service this year. Last fall, Tidal’s parent company, the Swedish technology firm Aspiro, said it had 512,000 paying users.

In addition, the broader market for streaming music includes YouTube and the Internet radio giant Pandora.

Tidal faces other hurdles, like whether Jay Z can attract artists from beyond his inner circle. And while Tidal may have the support of individual artists, in many cases the distribution rights to their music are controlled by record companies.

Lucian Grainge, the chairman of the Universal Music Group, said he welcomed Tidal’s arrival. “We like lots of services and we like lots of competition,” Mr. Grainge said. “Jay is an artist as well as an entrepreneur. He’s a winner, and we like winners.”

Speaking by phone from Los Angeles — where he was periodically interrupted by parenting duties for his 3-year-old daughter, Blue Ivy — Jay Z described his vision for Tidal as an outlet where musicians and fans “can all just camp out and listen to music,” and where artists would “always be on album cycle,” meaning in constant promotion mode.

Music executives briefed on his plans were more prosaic, calling it a hub for entertainment content and social media. Other ideas, like links for concert tickets and merchandise sales, have been discussed as possibilities.