Tell age of baroque wind instrument (9)
I believe the answer is:
flageolet
'wind instrument' is the definition.
(flageolet is a kind of wind instrument)
'tell age of baroque' is the wordplay.
'baroque' indicates an anagram (baroque can mean fancy or complex).
'tell'+'age'+'of'='tellageof'
'tellageof' with letters rearranged gives 'FLAGEOLET'.
(Other definitions for flageolet that I've seen before include "musical instrument" , "Pulse" , "Pipe" , "Small flute" , "Type of recorder" .)