A guitarist.
a guitarist
Call them anything you like, they won't answer back!
Guitarist
A "harmonicanist" is what a person who plays the harmonica is called.
solo
If by saying "not a guitar player" you mean someone who plays with a controller, then I would say generally people who play with the guitars are a lot better.
Well Tommy Emmanual is an example. Even Elvis, he played the acoustic guitar too!
are you meaning who plays the guitar for the tracks in the background
A bassist
An organist
a harmonist.
an "accordionist"