Ghanaian chanted a sea song (7)
I believe the answer is:
ashanti
'sea song' is the definition.
The definition suggests a singular noun which matches the answer.
'ghanaian chanted a' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ashanti that I've seen before include "encountered somewhere in Ghana" , "Ghanaian people and language" , "West African tribe" , "race" , "some Africans" .)