I think a concave neck for double bass/stand-up bass especially has great potential.
For a classical guitarists, it places the thumb directly behind the neck where it should be. Easier for small hands to access the strings too.
(especially a student) thumb rides up the wall of the neck and sometimes onto the fretboard.
A concave neck does not interfere with any existing techniques.
I've done a prototype with an electric guitar with the truss rod in mind (pic)
My SoundCloud page has more of my material, some Buddy, Jerry, & Speedy and some jazz legends I recorded.
Clicking on a song gives more info about the song.
Looking for a someone to license this idea.. Maybe a retrofit neck.
