Proper tune I chat about (9)
I believe the answer is:
authentic
'proper' is the definition.
(thesaurus)
'tune i chat about' is the wordplay.
'about' indicates an anagram.
'tune'+'i'+'chat'='tuneichat'
'tuneichat' with letters rearranged gives 'AUTHENTIC'.
(Other definitions for authentic that I've seen before include "Genuine, not a copy" , "reliable" , "Ian, the cut is genuine" , "Real, genuine" , "24 [LEGIT]" .)