Fit for a tango round the piano (3)
I believe the answer is:
apt
'fit' is the definition.
(thesaurus)
'a tango round the piano' is the wordplay.
'tango' becomes 't' (phonetic alphabet: alpha, bravo, charlie etc.).
'round' is an insertion indicator.
'the piano' becomes 'p'.
'a'+'t'='at'
'at' placed around 'p' is 'APT'.
'for' acts as a link.
(Other definitions for apt that I've seen before include "Relevant" , "Prone" , "may be appropriate" , "Fit, suitable" , "Train" .)