MIDI input from Apple Mainstage

[jjung]

I am fairly new to the show lighting world so bear with me. I need to take a MIDI signal from a keyboard (pretty simple) the concern is that keyboard is already plugged into a mac mini computer using mainstage. Mainstage can do a MIDI passthrough for an external instrument but my question here is will a usb a to usb a cable work between the mac mini and my raspberry pi running fpp 8? This is for a marching band show that will have lighting events triggered by our synth player. Any and all help is appreciated!!