Describe your system and your network for us.

Power burps are often deadly for electronic equipment. While ​@buzz  question is certainly valid, and useful, I’d be also tempted to reboot (via power cycle) everything, starting with the router, then moving on to the Sonos devices. 

In the title? You have to realize the forum doesn’t show that to folks using the “new post” forum tool? (You shouldn’t have to put up with that but it is what it is.)

Older Sonos S1 system. Power burp in house and cannot get sound working again. App says Sonos IS running

This seems to be a problem that hits some users and not others.

(As above) The quick fix is to power down ALL Sonos, reboot router and Controller, once back up power up your Sonos.

If it happens often you can usually do a more permanent fix by setting static/reserved IP addresses for all Sonos from your router’s DHCP settings page.