The patent describes a system whereby musical characteristics such as tempo (BPM) are shared with nearby users and the user's device will automatically select songs that are similar in nature. The system would transmit the digital information of a song being played by one user, or the "roving DJ" as the patent calls it, to any connected devices over the local network. Unlike traditional silent discos, where the same song is transmitted across radio frequencies, this system will use the songs that are already present on a user's device, presumably due to copyright reasons.
The technology is similar to the latest craze dubbed "mobile clubbing", where a group of people get together in one place and dance to their own music. Location, however, is not a deciding factor with Apple's system, as the signals can be transmitted over any means of wireless communication, including the Internet, Bluetooth and local wireless networks.
In other embodiments of the patent, users of the system can "rotate" DJs, so other people can select songs for the group to listen to. The patent notes that the system can be contained within one single application that is downloadable from the App Store.
Although this technology may not be implemented into any upcoming Apple products, it does present an interesting question of sharing music among iTunes users, which may be a key goal for Apple going forward. Its last foray into music-based social networking was Ping, which officially closed at the start of October last year after the service failed to impress its users.