On a remix of Kanye West's Grammy winning song, 'Diamonds from Sierra Leone,' Jay Z raps: "I'm not a businessman - I'm a business, man" - he's been throwing his financial weight around today, buying Aspiro, a Swedish music streaming company.
Mr Carter bought the company for 464m Swedish crowns (€50m) - the company currently operates two streaming services - the ad-free WiMP, and the high-definition Tidal.
Both of the services are marketed towards discerning listeners - offering streams and downloads in the lossless FLAC format.
WiMP was launched in 2010 and is currently available in Denmark, Germany, Norway, Poland, and Sweden - and reports to have 580,000 paying users. Tidal launched later, and is available in the US and the UK.
The acquisition will see Jay Z going head-to-head with Spotify, YouTube and Apple's new streaming services.
Apple bought Dr Dre and Jimmy Iovine's Beats Music for $3bn in May 2014. This deal included both the high-end headphone line, and its streaming service.
Beats' streaming software is currently being integrated into iTunes - and will be launched as a full Apple music-streaming product.
Music
Jay Z started his own record label, Roc-A-Fella Records in 1995. As hip hop gained mainstream popularity he was soon meeting with the major labels. He managed to retain ownership rights to his entire catalogue throughout his career.
In 2004 the label was sold to Def Jam for $10m. Jay Z was then made Def Jam CEO and president. The label enjoyed a string of global hits, launching the careers of artists like Kanye West.
Clothes
When Jay Z discovered that sales of Iceberg Apparel rose after he name-checked the brand in some songs, he approached the company to organise an endorsement deal.
He wasn't happy with the deal that he was being offered, so he set up Rocawear - his own apparel company.
It was massively successful - and he eventually off-loaded the company in 2007 - selling it to the Iconix Brand Group for $204m.
Clubs
In 2003 he got involved in New York's busy club scene - opening the 40/40 Club in Manhattan. Other outlets followed in Atlantic City, Las Vegas, Brooklyn and Hartsfield–Jackson Atlanta International Airport.
The Atlanta and Las Vegas clubs have since closed.
Sports
One of the self-proclaimed mogul's most high profile business interests was his stake in the Brooklyn Nets basketball team.
Although he was widely referred to as the 'owner,' the franchise was actually backed by a Russian businessman. Jay Z is reported to have invested $1m - and only owned one-fifteenth of 1 percent of the team.
He sold this stake in mid-2013 during the Net's first season in Brooklyn.
Once his formal connection with the Nets ended, he set up an agency to represent high-profile athletes - Roc Nation Sports.
Its clients included NFL players Vicotr Cruz and Hakeen Nicks - and NBA star Kevin Durant.
Auxiliary
He also has stakes in a champagne company, and a New York restaurant. Throughout his career he has had lucrative deals with some of the world's biggest brands. His last album was exclusively pre-released through Samsung phones.
Other recent connections include a promotional deal with battery-makers Duracell and an on-going tie-in with Budweiser. He fronts the company's annual 'Made in America' music festivals.
