I connected the micro-usb connection of the Roland GO Piano to this little box, and this onlocked a lot of new features.
Using the MIDI Out at this box the Go Piano can be used as a master keyboard to control other instruments.
When connecting a MIDI Controller (like the Roland A49) to the
MIDI In at this box, you can activate the hidden GM2-bank in the Go Piano, which gives you 128 additional sounds (!) to select through MIDI Program Change commands and then can be played on the piano keyboard.
By sending MIDI Control Change commands (like Resonance, Cutoff-filter, Modulation, etc.) it's possible to alter the sounds of the Go Piano, which leads to whole new sounds!