Apple Watch Series 4
I can't play music
Solution 2 of 6: The headset isn't working
Bluetooth is a wireless connection which is used to connect to your Apple Watch. You can also use Bluetooth to establish a connection to e.g. a wireless headset.
Press the Digital Crown.
Press the settings icon.
Press Bluetooth.
Press the required Bluetooth device.
Press the Digital Crown to return to the home screen.