Show the key in the door moving (5)
I believe the answer is:
rodeo
'show' is the definition.
(I know that rodeo is a type of exhibition)
'key in the door moving' is the wordplay.
'key' becomes 'e' (a musical key).
'in the' means one lot of letters goes inside another.
'moving' is an anagram indicator (letters are moved around).
'door' anagrammed gives 'rodo'.
'e' placed inside 'rodo' is 'RODEO'.
'the' acts as a link.
(Other definitions for rodeo that I've seen before include "Annually" , "Cattle round-up" , "Wild West show" , "cowboy carnival" , "skilful exhibition?" .)