Old Briton selected for audition? (4)
I believe the answer is:
pict
'old briton' is the definition.
(ancient people in Scotland during Roman times)
'selected for audition?' is the wordplay.
'selected' becomes 'picked' (picking is a kind of selecting).
'for audition?' indicates a 'sounds like' (homophone) clue (audition can mean hearing).
'picked' sounds like 'PICT'.
(Other definitions for pict that I've seen before include "Scotsman" , "Literary term for painted woman" , "Early Scot" , "Ancient north Briton" , "N. British tribesman" .)