@SomeGuy, make the Sonos play some music. Go to the IDE and go to the Devices tab. Select the Sonos and look under the current state section for the attributes Sonos publishes. Make note of whichever is relevant to the playing state of Sonos. Then stop the Sonos and refresh that page (may need to refresh the sonos in the ST app too?) - see if the status changed. Make note of the status that represents the stopped state, minding lower and upper cases - Groovy - the underlying language of ST - is as case sensitive as it gets. Then in the CoRE piston, make a condition for that attribute matching the exact status - you may need to enable Expert Mode to be able to select the correct attribute (an Attribute field will show up). Let me know how that went 