[vkou]

Sorry, I suppose being a professional musician is one field with similar requirements for skill versus pay. Nobody's going to pay any money to a middle-quintile piano player, just like nobody in academia is going to pay any money to a freshly-minted middle-quintile PHD.

[dalbasal]

Middle quintile?

[leereeves]

In percentiles, 40% to 60%.

[vkou]

Someone in the middle 20% of competence at a skill or profession.