Story is loud and competent (5)
I believe the answer is:
fable
'story' is the definition.
(fable is a kind of story)
'loud and competent' is the wordplay.
'loud' becomes 'f' (A musical term).
'and' says to put letters next to each other.
'competent' becomes 'able' ('able' can be similar in meaning to 'competent').
'f'+'able'='FABLE'
'is' is the link.
(Other definitions for fable that I've seen before include "It's not true" , "Story, often with moral" , "Mythological story" , "Aesop's story?" , "Myth, legend" .)