No, it is a plural proper noun. Here, the word African is the demonym for a person from or in Africa. It can be a proper adjective, but not as a plural.
Kentuckian is the proper adjective for Kentucky.
Africa - African
African is an adjective meaning "of Africa". In this case the adjective indicates the source of the music.
A proper adjective is an adjective formed from a proper noun. "Arabian", "Grecian", "Japanese", "African".
Egyptian is the proper adjective for Egypt.
The noun 'African' is a proper noun, a word for a person or thing of or from the continent of Africa.The adjective 'African' is a proper adjective, a word used to describe a noun as of or from the continent of Africa.
Middle Eastern is the only proper adjective in the sentence above. It describes "greenhouses."
A house in Africa is an African house. The word African is a proper adjective to describe the common noun house.
The proper adjective for southwest is "southwestern."
The proper adjective is Haitian.
The proper adjective for Portuguese is "Portuguese."