Solution:

Across many different genres, there are a handful of terms that are commonly used to refer to the various sections of a song. Much music, especially in genres that are related to pop music, is structured by combining these standard section types in a variety of ways. The most common sections are:

Verse or “A” Section: A song’s verse is generally a recurring section— usually 16 or 32 bars in length—that serves as the main body of the song. In music with lyrics, the verse often tells the “story.”

Chorus or “B” Section: The chorus is usually also recurring, and of comparable length to the verse. It acts as a contrast to the material of the verse and usually contains the “hook” of the song—a melodic idea that is intended to stick in the listener’s head. Often, the chorus serves as a point of musical resolution, while the verse creates musical tension. Another important distinction between verse and chorus: Recurring verses share the same music but they generally have different lyrics, while recurring choruses most often share both music and lyrics. Additionally, in music with lyrics, the chorus often contains the title of the song. As a general rule, the first chorus in a song occurs after a verse (although there are some songs that begin with a chorus).

Bridge or “C” Section: The bridge serves as a contrast to both the verse and chorus and typically occurs only once in a song. Musically, bridges are often substantially different from the rest of the music in the song; they may be in a different key, employ unusual chord progressions, or have a dramatically different level of textural density and energy. In some types of music, the bridge is used for instrumental solos. Generally, the bridge occurs only after at least one verse and one chorus.

The A, B, and C letter names are often used to create formal diagrams of particular songs, and this can be a useful tool in your own Active Listening or when writing a Catalog of Attributes. For example, one common form in commercial music is ABABCB or Verse-Chorus-Verse-Chorus-Bridge-Chorus. In some songs that use this basic form, there may be one or more additional choruses added to the end. But otherwise, this form is used unchanged in probably the majority of contemporary pop songs you’ll hear on the radio. “Royals” by Lorde is an example of ABABCB form followed exactly.

Although there is a wide variety of possible song forms that can be made just from various combinations of verse, chorus, and bridge, these types of sectional constructions are less commonly used in more underground or experimental music. For example, most contemporary electronic genres without vocals tend to avoid conventional verse and chorus sections, and instead create formal contrast via addition and subtraction of layers. But if you’re working in genres more closely related to pop music, you can create a lot of music using only these few section types.