The cloud music store is still in its infancy stages, with Amazon the only service to have had a full-fledged launch so far. Look for Google Music to officially join the ranks this Wednesday. Invitations were sent out Friday for an event to be held this Wednesday (16) with the tag line “These Go To Eleven.” In addition to being a stellar Spinal Tap reference, it can be assumed that the event has musical ramifications, likely that downloads will be added to their cloud music service. However, according to CNET, when the service launches, it will do so without Sony and Warner Music Group on board. Universal Music Group, the world’s largest label group, is allegedly on board, which is a good starting place.

Labels are anxious for there to be an iTunes competitor, and Google has reach, but without Sony and Warner on board, it’ll be tough for them to gain traction. There’s no word on whether EMI, which was just purchased by Universal, will be part of the Google’s launch. Amazon launched their cloud service without licenses from the major labels, and it hasn’t come anywhere close to having the penetration that iTunes has. The (not so) dark horse in this is Apple. They have yet to launch their full-on cloud service, but when it does launch, it will be with the blessing of all of the label groups. When it does launch, it’ll cost $25/year.

Google Music launched earlier this year as an online storage locker. As far as storing music, it did fine, but took a long time to upload music. The new  service is expected to integrate with Google+, the tech company’s answer to Facebook. That will give them somewhat of an advantage over Apple and Amazon, even if Google+ hasn’t quite taken off yet either. A Spanish website leaked what they claimed were screen shots of Google Music, even though the shots included Green Day (a Warner artist) and Shakria (a Sony artist). Apparently, there’s going to be a free song of the day, which is much like iTunes’ free song of the week. We’ll have to see how things shake out to see how Google will compete. Stay tuned for official word on Wednesday.