I am streaming , how can I play music when provider goes down.

I think some people confuse "service interuption" vs "network failure". The "Internet is down!" is a generic term for "things aren’t working". In the case of server/streamer/player, music files sitting on the server are not dependent on ISP functionality. As long as your network is healthy everything in your intranet should be just fine. No need to bring out the ukulele.

If things are not working and you are musically compromised, you can introduce a new topic to the group for discussion like: "Should birthdays be celebrated ON your birthday, and not another day that’s more convenient?" It could be quite engaging?

You "network guys" are something else.

I did home automation, distributed audio, home theater, security, etc. for several decades. Each time I’d attend (required) vendor training sessions on networking gear, I considered myself an expert for at least 45 minutes after the session was over. Then it was back to what I did best: configuring devices that made noise, or produced an image.

It could have been childhood trauma, but the "networking" section of my brain didn’t fully develop. You guys who can sling data around a home (without dropouts and dead spots) deserve accolades and (financial) rewards. You’ve earned it. These days, devices that make noise or produce images don’t make noise or produce images without a stable, reliable network. You win!