"We don't ask you for free iPhones. Please don't ask us to provide you with our music for no compensation," singer writes of streaming service's three-month free trial
CEO Tim Cook touts "the next chapter in music": A streaming service boasting entire iTunes library, music videos, a 24/7 radio station and way to "connect" with artists
Pink Floyd great also says of his former bandmates, "A reunion is out of the question"
As artists and industry executives vie for online supremacy, here's our ranking of the top players
"The Tides They Are-A Changing," the rapper tweets before launching his high-quality audio service