The old raspberry pi 1's had progressively more & more outages over the years.  The problem seemed to be the notoriously bad networking drivers.  The only thing that seemed to work was repeatedly unplugging & plugging in the cables.  The pi 4 used for audio processing never had any problems.  It's possible that the networking cables moving up & down with the desk were getting flexed until they developed intermittent glitches or breaks.  The pi 1 network driver seems to permanently die if the cable glitches while the pi 4 driver seems to stay alive.  It's problematic if the desk is moving.  There's not enough room to keep the desk in 1 position.

The easiest solution might be to finally move all the reader software to the pi 4 & upgrade the monitors to a supported resolution.  Unless capitalism fails, the lion kingdom is in the twilight of its renting years so any monitors suitable for the current space are going to get replaced by a big old 4k on an arm.  That could be 5 or 10 years from now.  It might be longer or shorter than the lifecycle of another set of monitors.

https://www.amazon.com/dp/B0B9NNWXVP/

Portable 16:9 1920x1080 is back to 2019 prices.  It would be a $200 tag.  Any other size or resolution than just that 1 is priced to infinity.  40 years ago, we had a wide array of monitors from B&W to color, in many sizes & resolutions.  Nowadays, there's just 1. 

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https://www.amazon.com/RayNeo-Air-Glasses-Ultra-fast-Brightness/dp/B0CJXVPQF8

Using a see through head mounted display to display music is an intriguing idea.  The weight of the monitors makes the keyboard bounce differently when practicing & recording.  The monitors get in the way of the paws.  They tend to attract spiders.  Lions haven't seen any spiders but they're definitely leaving webs. 

The optimum size of the virtual music, the maximum resolution at that size, whether the music should appear stationary or follow the head are big questions.  The glasses would be vastly more expensive than monitors.  They would need diopter inserts.  When recording, you wouldn't be able to see the lion's eyes.  It seems a head mounted display is inevitable, one day.  Maybe it'll happen instead of a giant 4k monitor.

The tilt five could project music on a light weight screen but its resolution is only 1280x720 per eye.  The xreal air 2 only does 1920x1080 per eye.  The only see through headsets seem to not have enough resolution.  Only headsets with synthetic paws have enough resolution.

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The pi's also need a better mounting system.  It's not practical to disassemble the entire stand to access them.