Just not enough information given to really know the source of your issue, so I’d try a few things. First, unplug all your Sonos devices from power. While they are unplugged, reboot your router. Once the router comes back up, plug back in your Sonos.

While you’re at it, make sure the router has the latest firmware, and make sure your Sonos is up to date, there was a recent release of new software/firmware. 

Since we don’t know the source of the music, check the Sonos real time status page to make sure there isn’t a known issue currently with the streamlining company you’re trying to use.

If none of that helps, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.