Google defended its music storage service at a press conference today shortly after it unveiled the service at its developer conference here.

The new Google Music service, which  allows people to store up to 20,000 songs in the Internet “cloud.” The benefit of doing this is that they will then be able to access the music from any Web browser that supports Flash or Android devices. The service is still being beta-tested and will only be offered to a select group of invitation-only users in the U.S. Initially, the service will be free to users, but Paul Joyce, a Google project manager demonstrating the service during the keynote this morning at Google I/O, hinted that Google may charge for the service in the future.

He also hinted at capabilities being added to the service in the future. But for now Google only will allow music to be stored remotely. It won’t allow users to purchase new music via the cloud.

Jamie Rosenberg , direct of digital content for Android, answered a question from a reporter about whether Google was afraid that music studios would take issue with Google allowing its users to move music digitally across the Internet. He responded by saying that the service is “completely legal,” because it allows people to store only music that they own legally. Rosenberg admitted that Google had wanted to offer music labels an opportunity to sell music to Google users through the cloud service, but that the labels had asked for certain conditions that Google couldn’t accept.