A song is a musical composition written to be sung by the human voice. It is distinguished from other types of music, such as classical instrumental music and opera.
A song can be sung solo by one singer, by a duet or trio (where two or three singers are singing together), by a larger ensemble involving more voices singing in harmony, or by instrumentalists accompanied by the human voice. It may also be sung without accompaniment, which is known as a cappella.
Introduction
A typical introduction to a song is slower and more low-key than the rest of the music, to catch the listener’s attention, but not overwhelm them. It should establish the rhythm, tempo, and melody of the song and introduce the singer or singers’ voices.
Lyrics
A song’s lyrics are its most important component, and can make or break it. They tell a story, convey emotions, and express a person’s identity.
They are also often very difficult to write, since they have to match the complexity of the music and resist changes.
The chorus
In contrast to verses, which come in gradually, a chorus is the moment when all of the big ideas in a song are brought together in one place. It is the point at which the tension in the song reaches its peak, and should contain a hook.