An example of custom engineering would be the Bass Skitz (a.k.a. Schizotron) designed by Guess Musical Instruments. The Schizotron is a bass guitar with a keyboard attached. WindWorks Design designed and built the custom midi electronics embedded into this unique patented instrument. When the player switches into neck/enable mode the bass neck becomes a one handed midi controller, with each note producing a midi signal. The player is able to finger midi bass notes with the left hand while playing chords on the keyboard with the right hand. This is not a typical midi-guitar system, but a unique patented design powered by custom midi electronics designed and built by WindWorks Design.
The Schizotron is not available for sale. It was a one-off custom design for a client.