March 4 (Reuters) - Payments firm Square Inc on Thursday agreed to buy a majority ownership stake in Tidal, a music streaming service owned by rapper Jay Z, for $297 million in cash and stock. Square, co-founded by Twitter Inc Chief Executive Officer Jack Dorsey, said Jay Z, whose real name is Shawn Carter, would become a member of Square’s board of directors. “Why would a music streaming company and a financial services company join forces?!... It comes down to a simple idea: finding new ways for artists to support their work,” Dorsey said on Twitter. Square did not disclose the percentage of the ownership stake. Tidal calls itself an artist-owned service backed by Kanye West, Beyoncé, Madonna, Rihanna and Nicki Minaj among others, and is available in more than 56 countries. Tidal will operate independently within Square and existing artist shareholders will be the remaining stakeholders, Square said in a statement. Jay Z bought Tidal for roughly $56 million in 2015. (Reporting by Noor Zainab Hussain in Bengaluru; Editing by Ramakrishnan M., Bernard Orr)