Sean Angus Watson, an artist and guitar teacher in Oregon, performed a really incredible funk solo on a fretless baritone six-string guitar that was custom-made by his friend luthier Drummond Fudge.
Looks and plays exactly like a normal guitar except it doesn’t have frets and it’s tuned down nearly an octave. …To give you a sense of the range, the low G string is the same pitch as the 3rd fret on a bass guitar’s low E string. The lowest note on a normal guitar is two whole steps above the 5th string on this guitar.
Watson had spent some time experimenting with this guitar before playing this solo.