One who plays the organ. Organists have an interesting culture, which is also very diverse. An organist might play any sort of organ (pipe organ, Hammond, theatre). And, there are many types of organist-
The Diva-
These organists will be inclined to jump up behind the conductor at somebody else's choral recital and give cues as they see fit.
Non-technical
player-
Somebody who just knows how to turn the blower switch on and pull out the right stops. The have no idea how an organ pipe works, and now much of a clue how the organ itself works.
Old lady-
Yeah, the old blue
hair that plays the organ at the
local Roman Catholic parish. She never pulls out any more than three stops and likes to take it
slow.
The 50% organist-
A pianist who is passing for an organist. They usually play on
one manual and don't use pedals. Enough said.
The good organist-
These organists can play both Bach and
French Romantic, as well as many other types of organ music. They can register well, and play cleanly. Fortunately, such organists are usually well mannered.
The passable organist-
This organist can play hymns well, but not much else. Fugues may confuse them, and sometimes they can't register that well. They are good for regular, nothing
special Sunday services.