Angel in south-east playing harp (6)
I believe the answer is:
seraph
'angel' is the definition.
(seraph is a kind of angel)
'south-east playing harp' is the wordplay.
'south east' becomes 'SE' (abbreviation).
'playing' indicates anagramming the letters.
'harp' with letters rearranged gives 'raph'.
'se'+'raph'='SERAPH'
'in' acts as a link.
(Other definitions for seraph that I've seen before include "Phrase for a lofty angel" , "Angelic character" , "Angel - phrase (anag)" , "Leading angel" , "He raps the heavenly being wrongly" .)