On this instrument you can play bass and guitar on one neck. Of course that is if you can play the guitar! Four strings bass to a bass-amp and completely separated–four strings guitar to a guitar amplifier. So you can have any effect you desire on the guitar at the same time with no interference–a nice clean bass sound.
I thought this instrument up in 1965. The first instrument was built by the English firm Vox. Today, together with Stuart from Cassandra Elk instruments Vootar 4 is being developed.
This instrument is particularly useful for when you play in a small band like I did with Paddy, Klaus & Gibson so you can accompany the guitarist with bass and rhythm guitar whilst the drummer is freaking out.