A song is a short poem or other set of words that are put to music and meant to be sung or rapped. This is a very broad definition, but it covers all the things we associate with songs in our culture, including pop, rock, country and classical.
Lyrically, a song is an opportunity to tell a story that evokes emotion. It’s often in the chorus where this is achieved, as it serves as the big payoff and climax of the song. It’s also where the biggest energy usually comes from, and where you’ll often find massed voices singing in harmony. The chorus is also a good place for songwriters to experiment with harmonies and other arrangements, to build upon the familiar chord progression from the verse or pre-chorus.
Musically, a song is the combination of melodies, lyrics, and grooves that make it tick. Many musicians are wary of learning how to break down a song into its bare elements, fearing it will make their music less “real.” But the truth is that knowing the vocabulary helps you better understand and communicate with your collaborators.
To analyze a song, researchers measure the musical components in four ways. For example, they measure how complex a melody is by counting the number of different pitch classes that appear in it. They also measure the amount of ornamentation, or the way in which a melody repeats micro-meter groups (like beats) to create rhythmic structure. Finally, they look at the interval size, or how much variation there is between pitches in a song.