You can set up the Remote app on your Apple Watch to play music on your Apple TV. To use the Remote app, set it up with your Apple TV or in iTunes on your computer. You only need to set up the app once for each device, and you can remove devices later. After you set up the app, you can quickly choose what to control from your smartwatch.
First, set up your Apple TV and the Remote app:Make sure that your Apple TV and your Apple Watch are on the same Wi-Fi network.
- On your Apple Watch, open the Remote app, then tap Add Device.
- On your Apple TV, select your Apple Watch:
- Apple TV (4th generation): Go to Settings > Remotes and Devices > Remote app, then select your Apple Watch.
- Apple TV (2nd or 3rd Generation): Go to Settings > General > Remotes, then select your Apple Watch.
- On your Apple TV, enter the passcode that appears on your Apple Watch. When the pairing icon appears next to your Apple Watch, you can start controlling your Apple TV.
After you set up the Remote app, you can control your Apple TV. Make sure that your Apple TV is awake, open Remote on your Apple Watch, choose your Apple TV, then use these gestures:
- Swipe up, down, left, or right to move through the Apple TV menu.
- Tap to choose a highlighted item.
- Tap Menu to go back, or touch and hold it to go to the Home screen.
- Tap the pause/resume button to pause or resume playback.
(This how-to is based on my experiences and info on Apple's support pages — where the images sometimes come from.)