What is the purpose of a music video

Sell a song. A music video helps to provoke a reaction for the audience and leaves the audience remembering the song.

Sometimes a music video gives a listener a understanding of the song. If the music video is narrative.

To entertain the listener.

To show off the artists talents whether, just singing or other things as well. For example in Chris brown's music videos he tends to dance.

Increase exposure.

We can also understand that although a music video is used to help create a story and atmosphere behind a piece of music, they are used mainly as a promotional tool for the artist to increase the attention and sales.