For both keyboard and guitar finger movements can be very subtle and therefore difficult to discriminate. Probably easier if your camera can be mounted to give

For both keyboard and guitar finger movements can be very subtle and therefore difficult to discriminate. Probably easier if your camera can be mounted to give top-down view of your fingers while playing the keyboard. Probably much harder on guitar since getting a good view of how the fret is fingered is hard. Fingers may also hover over strings or lightly press strings to mute them.