In the world of online music, iTunes has long reigned supreme.  It enjoys such a dominant position that it is currently the subject of a U.S. Federal Trade Commission inquiry investigating whether it abused smaller competitors like Amazon.com.

Apple's days as the only big player on the market may be numbered, though.  At Google's I/O conference last month, the company previewed a web-based service for developers.  AndTechCrunch two weeks ago discovered a "Google Music" logo hosted by the company.  Now CNET has joined the buzz, citing numerous industry sources as saying a launch of Google Music could come as soon as the fall.

Google enjoys one critical advantage that could allow its rebel service to ultimately crush Apple's music empire.  That advantage is search.

Close to a billion users visit Google every day, many of them searching for bands, songs, and album titles.  By tying these searches to subscription-based streaming services and web-based digital downloads akin to iTunes, many music executives believe that Google may promise more sales than Apple.

Its rivals have tried to keep Google out of the music business.  After Lala and iLike teamed with Google to offer streaming music with searches, Apple snatched up Lala and Myspace acquired iLike and both companies shut down the streaming.

The decision by Google to launch its own service is like a dream come true for music labels.  They are reportedly fed up with Apple, which currently sells over one quarter of the total music sold (digital or otherwise).  However, the current competition -- Amazon.com and Myspace Music -- lack the sales to pose a serious threat, which means that Apple gets to dictate whatever terms it wants to the labels.  That's a situation that they're not very satisfied with.

Zahavah Levine, YouTube's general counsel who previously worked with RealNetworks' Rhapsody music subscription service, is reportedly working to cook up the new service.  YouTube has already enjoyed success in the music business thanks to its plethora of music videos.

Google's new service reportedly will have many unique features.  Among them will be the ability to stream music from a library on your PC to your Android smartphone.  Google picked up a company called Simplify that developed this technology.  Google's service is also reportedly going to be cloud based -- available exclusively as a web application.  While Apple is also reportedly working on a cloud version of iTunes, Google reportedly wants to beat Cupertino to the punch.