Father tries moving piano first (6)
I believe the answer is:
priest
'father' is the definition.
(I've seen this before)
'tries moving piano first' is the wordplay.
'moving' is an anagram indicator (letters are moved around).
'piano' becomes 'p' (musical abbreviation).
'first' says to put letters next to each other.
'tries' is an anagram of 'riest'.
'riest' after 'p' is 'PRIEST'.
(Other definitions for priest that I've seen before include "Member of the clergy" , "Minister of religion" , "Religious minister" , "Religious functionary" , "Church minister" .)