For troubleshooting purposes, try hardwiring the Play 1 to your router to see if the problem persists. If that fixes the problem, you may want to consider how to make it a permanent solution.

Because of the older hardware inside the Play 1, they sometimes struggle to perform at the same level as newer speakers. If you have no issues with other speakers, this may be your issue. I have a Play 1 that has always been hardwired to my network. I have not had any connection issues with this configuration.

Thanks for you idea. I will tes this. But I am concerned about two things: I don’t see how, based on the placement of my speakers, how the Play:1 can be tethered to the router, second I notice that this connectiton issue occurs when I connect through the S2 Controller’, it connects but drops intermittently with a message that the program’s content is ‘encoded incorrectly‘. Do you think Sonos will provide a microcode update to correct this?

I’d doubt a ‘microcode’ update, but that sure sounds like some wifi interference or a duplicate IP addresses issue causing the PLAY:1 not to connect to your router, and receive a ‘clean’ stream of music. 

​@Pools-3015 suggestion could be tried temporarily, in order to indicate the potential cause, by simply moving the PLAY:1 into a position where it can be temporarily wired with an Ethernet cable. Once you’ve  fixed the issue, you could move it back. 

I did as @Pools-3015 suggested.  And when the Play:1 is hardwired to the router there are no problems with the connection.  I have a second Play:1 in another location and I experienced the same error symptoms. Can you provide the steps to seeing if I have duplicate ip addresses?  Thanks.

Just an update. I figured out how to the ip addresses of the Sonos devices and I found no conflicts or duplicate assignments.  
For kicks and giggles I tried to re-add the Play:1 on my iPad; I got a ‘1,000’ error.  I went to my AirBook and got a notification to update the S2 controller software. It is always a problem updating through the app, so I downloaded the new release. After it installed successfully, it prompted me to do an update for the devices.  That failed. I went back to my iPad and did the device updates and an update for the Play:1 appeared and was completed successfully.  And testing so for has not had any errors.
I have a second Play:1; I will check on that tomorrow.

Thank you for your assistance.

The second Play:1 now works also.