CNET: Streaming music service Tidal has relaunched with high-quality audio at $9.99 a month as the artist-owned alternative to the likes of Spotify, backed by Jay Z and more than a dozen other well-known musicians. However, the unveiling event packed with music megastars didn’t indicate whether those artists or others would contribute exclusive music to Tidal, which would make it the only place to hear some of the world’s most popular artists.