What is the function of a music video?

In our first class we discussed on what we believed to be the function of a music video.
What we discovered was the the function of a music video is to promote the music artist as well as advertise their songs. Giving the audience more options to how listen to the music.
Having a music video advertises the artists, giving them more publicity on television as well as youtube, rather than just radio.
What I notice in music videos is that it can also show a deeper meaning in the song that the listeners wouldn't recognise from just listening to it on the radio, giving some song writers an opportunity to express the depth of their song through the video.