Along with Mac OS X 10.11.2 and iOS 9.2, Apple has released tvOS 9.1, an update to the operating system of the fourth get Apple TV. It introduces support for Siri search for Apple Music, which lets Apple TV owners ask Siri to play content from Apple Music.
The tvOS update includes several bug fixes. It also features improvements to networking and scrolling.
tvOS 9.1 can be downloaded via the Settings app on the fourth-generation Apple TV. Go to the System app, then to Software Update (under the Maintenance subhead.)