violonisto

This is the word the violono page promised. Take the instrument, add -ist-, and you have the person who plays it, exactly as instrui gives instruisto and ĵurnalo gives ĵurnalisto. Nothing is memorised here: if you know the root and you know the suffix, the word is already yours, and so are pianisto, gitaristo and flutisto.

Be careful about what -ist- claims. It marks a settled occupation or an allegiance, not a one-off action. A violonisto plays the violin for a living, or at least seriously enough that it is part of who she is; someone sawing away at one on a wet Tuesday is a violonludanto, or simply homo, kiu ludas violonon. The same distinction is why an Esperantisto is a speaker of the language as a commitment rather than anyone who has ever said saluton.

The story La konkurso is about precisely this word without ever using it. Its narrator writes her own name on the board and the word violono after it, and the whole tale turns on whether she is entitled to the -ist- yet. That is a fair reading of the suffix: it is a claim about yourself, and it takes some nerve to make.