The standard electric guitar is polyphonic, but the pickup ultimately sums all the notes down to a single output – which can be limiting as strings can’t be processed individually.
One solution was to create a 2 voice pickup that could split the outputs of the top and bottom 3 strings. Here’s a potential use case : a portable one-man band setup with a 2 voice instrument around the guitar which would allow a guitarist to process their strings individually to play bass register notes and normal guitar notes at the same time. When combined with hybrid picking styles (a la Martin Carthy and Chet Atkins), an octave pedal and some careful chord fingerings, it would be possible to play the simultaneous lead and bass lines.
This could be achieved with a fairly simple setup – two pickups, each amplifying only 3 strings of the guitar. Read more about it on our post at Banana Apparatus