Getting the pitch in good order (6)
I believe the answer is:
tuning
'order' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'getting the pitch in good' is the wordplay.
'getting the pitch' becomes 'tun' (I can't explain this - if you can you should believe this answer much more).
'good' becomes 'g' (abbreviation).
'tun'+'in'+'g'='TUNING'
Can you help me to learn more?
(Other definitions for tuning that I've seen before include "- Fork aids a musician" , "Adjustment (which can be fine)" , "Calibrating to a standard frequency" , "Modifying vehicle engines to improve their performance." , "Adjusting (eg, a piano)" .)