Rap mogul Jay-Z celebrated his fiftieth birthday and surprised fans Wednesday by putting his catalogue back on streaming giant Spotify, after a two-year hiatus.

The billionaire artist, who owns rival streaming service Tidal, had pulled the majority of his discography from Spotify in 2017, months before dropping his “4:44” album exclusively on his own upstart platform.

The introspective album prompted a surge of interest in the paid subscription service Tidal — which also exclusively carries his megastar wife Beyonce’s much-touted visual album “Lemonade” — briefly becoming a top downloaded app

Fans can now stream “4:44” on Spotify for the first time, along with classics like “The Blueprint,” “American Gangster” and “Watch the Throne.”

The rapper has the second-most top albums in the history of Billboard’s rankings chart with 14, bested only by The Beatles, who have 19.

“Happy Birthday, Hov,” Spotify tweeted Wednesday, using a nickname of the rapper born Shawn Carter, who grew up in one of Brooklyn’s most notorious housing projects.

There was no indication how long Jay-Z’s flow would remain available on Spotify, which has often come under fire from prominent artists including Prince, Taylor Swift and Thom Yorke for its royalty system, which many musicians say leaves them underpaid.

In June, Forbes declared Hov rap’s first billionaire, estimating $100 million of his vast fortune came from Tidal.

As of 2016, Tidal said it said it had 3 million users.

Today, Spotify says it has 248 million users, including 113 million who pay for premium service.

(AFP)