Google Music: 7 Key Facts

In a challenge to Apple, Amazon, and dozens of music startups, Google has launched Google Music, an online music platform that combines the company's cloud-based streaming service with Google+ and Android Market.

In May, Google introduced a preview version of its music streaming offering, Music Beta by Google, an effort that has been overshadowed by Facebook's recent partnership with a more popular music streaming service, Spotify.

At a press event Wednesday in Los Angeles, Jamie Rosenberg, director of digital content for Google, said that service, now called Google Music, is available to everyone in the United States. He described it as an effort to improve the digital music experience.

Here's what you need to know: