The function of metaphor in songs is much like its function within poetry and other written works: to relate two different things to each other to provide a deeper meaning or understanding of each. This can be done in a fairly obvious way, which often creates a metaphor on the surface level, or it can be deeper and utilize an extended metaphor. Musicians can also utilize metaphors in the title of a song to make the title stand out more and capture the attention of an audience more quickly. Many songwriters and lyricists use metaphor in songs to make personal experiences more universal and connect more strongly with a listener.
A metaphor is created to establish a connection between two things to reinforce some concept or idea. The song Dust in the Wind by Kansas, for example, utilizes the metaphor that “All we are is dust in the wind” to draw a comparison between humanity and particles of dust blowing around. This serves to reinforce the ephemeral nature of mankind, creating a sense of formlessness in the mind of the listener. Such a metaphor in songs can also reinforce other ideas, such as the association of people with dust as a way to conjure the phrase “ashes to ashes, dust to dust” in the mind of a listener, which is often spoken at a funeral.
Metaphor in songs can also be used to create a stronger title. In the above example, the very title featuring half of the metaphor found in the song begins to introduce the comparison to the listener before he or she even hears it. The image of dust blowing in the wind is immediately evocative and allows the listener to begin entering the right state of mind to appreciate the lyrical content of the song. This use of metaphor in songs also makes the title of the song more memorable for a listener, allowing him or her to find it later and listen to it again.
Some songs are, themselves, extended metaphors conceptually, with other metaphors and devices running through them as well. The Pink Floyd song Shine On You Crazy Diamond is a reference to previous Pink Floyd singer Syd Barrett and his struggles with mental health. This sense of insanity, and the persistence of human nature in spite of such difficulties, is evoked by the metaphor within the song title. The entire song reinforces this concept, with other devices, including the simile “Now there’s a look in your eyes, like black holes in the sky,” which further develops themes of losing a friend to mental illness.