How do I sync both my iPad Pro 9.7 and iPhone for Apple Music so that when I click a song it show up on other device

Hi jcoh,

Thanks for using the Apple Support Communities! I'm sure we can help you out with your question. If you are looking to set up and sync Apple Music across all your iOS devices, you may find the information and steps outlined in the following article helpful:

Sync Apple Music across your iPhone, iPad, iPod touch and computer - Apple Support

Regards

If both devices are signed into the same Apple ID they should automatically see the same tracks in the Library listing of My Music. Meaning if you add a track/album from Apple Music on one device, the same album/track should also be added to the second device.

However, if you mean you download a track to one device to listen to without using cellular/wifi data, that track will not automatically be downloaded to the other device or computer. You have to go through the download procedure separately for each device/computer.