People who play instruments use mainly two titles in the music business: 'professional musician' and 'artist'.
I thought about this after I got sent this video. Don't worry about the clickbait title—there's a real message here.
The sender told me that this church pianist was the same age as me and that his thoughts bounced off mine in some fun ways.
For the link above, I chose the timestamp where he says:
"You need to be well-rounded in every aspect when it comes to church, because you never know who will hire you. I can play for any type of church."
What 'professional musician' means
'Professional musician' means "I can play for any X." If you can't, you're not really a professional musician.
I can play for any folk band, any restaurant with jazz, any band that tours midsize Canadian festivals and needs an upright bass player, any community stage band with a concert who needs a ringer. I have proof for all of those cases: videos, audio, and references from colleagues.
I can't play for any hip-hop or country show or prove that I could. But if you can, you're a better professional musician than me by definition.
Your ability to back up the statement, "I can play for any X in your genre" is the value of your skills as professional musician. That's what you sell.
What about 'artist'?
'Artist' can mean you're selling to yourself instead of to others. But in broader context it means you are selling a brand of yourself. The versatile skill that 'professional musicians' are selling doesn't matter for 'artists'.
You can be as artistically stubborn as you want and it might appeal to people even more as a result.
Many music careers, including mine, mix these two identities. However, when a 'professional musician' is on the job, it's better that they're not an 'artist' and vice versa.
We increase our overall potential when we give these identities the separation they deserve.