Changing source on apple watch

The behaviour of Music on the watch has changed with successive watchOS releases. So far as I can tell, its no longer possible to select source from the Watch music app - The Music app on watch is now only for music locally stored on the Watch of for Watch access to Apple Music.

Here is how things seem to work with watchOS 4.2:

If you want to play music from your phone, but want to get things up and running from the Watch, try using Siri on the watch:

Hey Siri play Night At The Opera by Queen

This will load that album up on your phone and you can use the watch to skip tracks, change volume etc.

Similarly, if you get things playing using Music or Siri on the iPhone, your watch will let you control the audio.

If you have music loaded on the watch, or if you have the LTE model, then you can use the Music app on the watch to select what music you want to hear - sourced from the watch.

You've made a few comments about battery life when playing music from the watch, is this based on experience, or based on what you have heard?

There are two sources of potential battery drain - one is bluetooth from the watch - and may depend on what headphones you have paired. Particularly if they don't support Bluetooth low energy.

The other is LTE battery drain if your watch is playing music from the cloud.

I would have thought battery drain would be quite moderate if its just bluetooth to your headphones.

Also, the quality of music playback may be lower from the watch than from your iPhone - this could depend on the iPhone model and the headphones you are using.

In particular, music streaming by the watch seems to be at a reduced bitrate than to the iPhone.

I hope these notes are of some assistance to you.

Regards
Tim