Music of spirit (4)
I believe the answer is:
soul
I believe this clue is a double definition.
'music' is the first definition.
(type of music)
'spirit' is the second definition.
(I know that soul is a type of spirit)
'of' acts as a link.
(Other definitions for soul that I've seen before include "Immortal spirit; music style" , "Deep feeling - music genre" , "Spiritual part of a being" , "Individual; type of music" , "Spirit, inner self" .)