Ferdinand de Saussure

Here is a useful Slideshare that I found that explains Saussure's theory of semiotics:

Applying this to music videos:

In this shot from 'Snap Out of it' by the Arctic Monkeys, the signified is the idea of sadness, this is shown through the signifiers of the black nail varnish (black has connotations of death, mourning, sadness) and smudged makeup and tears (showing that the woman has been crying).

In this shot from Ed Sheeran's 'Thinking Out Loud', the sign of the dancing woman signifies femininity and sexuality, the silhouette emphasising her body. The sign of the colour red also signifies sexuality as red connotes passion and love.