Country and western and Hillbilly music

Country and western noun - A simple style of folk music heard mostly in the southern United States; usually played on stringed instruments.

Hillbilly music and country and western are semantically related in folk-style music topic. In some cases you can use "Hillbilly music" instead a noun phrase "Country and western", when it comes to topics like country and western music.

Hillbilly music noun - Country music originating in mountainous regions of southern United States.

Country and western and hillbilly music are semantically related in folk-style music topic. You can use "Country and western" instead a noun phrase "Hillbilly music", if it concerns topics such as country and western music.