One picked to appear in concert? (6)
I believe the answer is:
guitar
'one' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for guitar that I've seen before include "Six-stringed instrument" , "Fretted string instrument" , "Popular stringed musical instrument" , "13's lute" , "Stringed instrument often played by pop groups" .)