So what is Jay Z thinking? He turned 45 in December. The onetime street hustler is now a husband and a father and hobnobs with world leaders such as President Obama and Nicolas Sarkozy, the former president of France. Some say he has grander ambitions in middle age. “He’d like to be a billionaire,” says Rob Stone, co-founder of the Fader, a magazine that extensively covers the rap world. “He’s talked openly about that. But I think in his mind, it’s no longer just about how much money he’s making. It’s about his legacy and what the name Shawn Carter will mean after he’s gone.” He wants to save the music industry from the brutal economics of streaming—and make himself a fortune in the process. So far he’s doing neither. ... For Jay Z the entrepreneur, the challenge was plain: Find a way to capitalize on the technology industry’s takeover of the music business beyond being a high-priced shill. ... The losses didn’t frighten Jay Z. He offered a 60 percent premium over Aspiro’s market value, according to a filing, and repositioned it as an artist-friendly alternative to Spotify that would pay higher royalties to record labels and artists. ... You can still listen to the catalogs of virtually every Tidal owner on Spotify. ... It’s too early to write off Tidal. But if the company does fail, it may be because Jay Z didn’t anticipate the skeptical response to his claim that he was working for some greater good of all musicians.