What is the significance of "singing benna in sunday school" in Kincaid's "Girl"?

Kincaid uses several references to set up standards of
behavior in the story "Girl."  In the story, the mother tells her daughter that she must
not sing benna in Sunday school.  Benna is a type of West Indian music that draws close
comparison to calypso music.  The energetic tones of this type of music are in sharp
comparison to the reserved nature of church and religion, and therefore, the mother
tells her daughter that shse must leave this type of music for another time and place. 
The mention of this music is significant because it is an example that allows the reader
to get a sense of the cultural context in which the story in
situated.