It was a random thought and would be beyond my ambition (if not skill) to make work, but... Would it be feasible to build a Raspberry Pi into the body of a guitar or bass, wire it with a DAC cable to USB, put another Raspberry Pi connected to the amp the same way, and connect the two via 300N wireless on 5GHz band? I wouldn't even expect to need custom software or drivers, I believe everything needed already exists. And, yes, you could set it up so you could use a Bluetooth keyboard and display over Bluetooth or wireless, and sit around backstage or in a van using your instrument to play games. I ask because I have a friend who is trying to find a project to work on with his son that uses Raspberry Pis, they also are both just starting out on guitar, which would increase his son's interest. I would even use them myself if the latency was under 5ms.