Song structure: the parts of a song, common forms, and how sections are counted in bars

Song structure is the order of a song's sections. Pop and rock songs nearly always have verses and a chorus, and the most common order in modern popular music is intro, verse, pre-chorus, chorus, verse, pre-chorus, chorus, bridge and chorus, with an optional outro. In many styles, each section is built from short patterns combined in multiples of four, eight or 16 bars.

The parts of a song

• Intro: opens the song and sets its feel and key, usually without vocals.
• Verse: tells the story. Each verse uses the same music with new lyrics.
• Pre-chorus (optional, also called a build or channel): connects the verse to the chorus, often with new chords that make the chorus feel like an arrival.
• Chorus: the main idea of the song, and usually where the hook is. It keeps the same lyrics each time it comes back and is bigger than the verse.
• Post-chorus (optional): a section right after the chorus that keeps or raises its energy and carries a hook, often a repeat of the chorus hook.
• Bridge: breaks up the repetition with different music and words, usually after the second chorus, before the last chorus. A middle eight is a common type of bridge.
• Solo (optional): an instrumental section, common in rock and often after the middle chorus.
• Outro: ends the song as the energy winds down, often with a fade-out or a repeated part of the chorus.

The verse, pre-chorus and chorus usually repeat through the song, while the intro, bridge and outro are usually played once.

A song map: one example in bars and minutes

Laid out like this, the song is 92 bars, which at 120 BPM is 3 minutes 4 seconds: in 4/4 each bar is four beats, so a bar lasts 2 seconds at 120 BPM. Change the tempo and the same bars take more or less time. To time a song you like, find its tempo with the BPM tapper or the key and BPM finder, then count its sections in bars.

How many bars are in a verse, chorus or intro?

There is no fixed number, but in many styles sections are built in multiples of four, eight or 16 bars, so a verse or chorus of 8 or 16 bars is a safe place to start. In hip-hop, 16 bars is the length rappers are generally given for a guest verse. The classic 32-bar form uses four sections of most often eight bars each, and a 12-bar blues verse is, as the name says, 12 bars.

Intros have gotten much shorter. A study by Hubert Léveillé Gauvin, published in Musicae Scientiae, measured how long 303 US top 10 singles from 1986 to 2015 ran before the voice came in; Inside Radio reported that the time fell from about 23 seconds in 1986 to about 5 seconds in 2015.

This table shows how long 4, 8 and 16 bars of 4/4 last at common tempos:

Each value is bars times 4 beats times 60, divided by the tempo in BPM. In 3/4, use 3 beats per bar: 8 bars at 120 BPM last 12 seconds.

Common song structures

Verse-chorus form

The form described above, and the most common in modern popular music. The chorus often contrasts sharply with the verse in melody, rhythm and harmony, with more energy and often added instruments; this is known as a breakout chorus. In simple verse-chorus form, as in the 12-bar blues, the verse and chorus share the same chords. Written as letters, verse, chorus, verse, chorus, bridge, chorus is ABABCB.

AABA (32-bar form)

Four sections, most often eight bars each: two A sections, a contrasting B section (the bridge, or middle eight), and a last A. It is common in Tin Pan Alley songs and other American popular music of the first half of the 20th century, and in many jazz standards, such as "I Got Rhythm".

Strophic form (AAA)

Every verse is sung to the same music, with no contrasting section; if there is a refrain, it comes back as part of each verse. Many folk songs, ballads and hymns are strophic, and so is the 12-bar blues.

12-bar blues

A 12-bar pattern built on the I, IV and V chords of a key. In its basic form in C, the bars run C, C, C, C, F, F, C, C, G, F, C, G, and each verse repeats the pattern.

Hip-hop

Verses alternate with a hook, which in hip-hop is often the chorus itself.

Dance music: build-up and drop

In electronic dance music the high point is the drop, a sudden change of rhythm or bass line that follows a build-up and a break, and it is usually the loudest part of the track. Many dance tracks have more than one drop, and in vocal dance-pop a drop may come with each chorus.

How long should a song be?

As long as the song needs; there is no rule. But hits have been getting shorter. Billboard reported on 4 June 2019, using Hit Songs Deconstructed's data, that songs reaching the Hot 100 top 10 for the first time in 2019 averaged 3:07 so far that year, 30 seconds shorter than 2018's average of 3:37. From 2015 to 2017 the average had moved only between 3:32 and 3:43. Songs under three minutes made up 39% of those 2019 top 10s, up from 4% in 2016, and hip-hop top 10s averaged 2:48. The example map above, at 3:04, sits in that range.

Make each section sound different

Structure only works if the listener can hear the sections change. Give the chorus more than the verse: more instruments, more energy, backing vocals (the chorus is named after the backing voices it often adds). Change the words and the music in the bridge, and let the energy drop away in the outro. On vocals, Burnish Vocal Chain's DOUBLE station adds two or four doubled voices, with detune, timing, width and level controls: use it on the chorus vocal to make it wider than the verse, and check the result in mono. For the whole process from idea to finished track, see how to make a song.

Questions

What are the parts of a song?

Intro, verse, pre-chorus, chorus, post-chorus, bridge and outro, plus a solo in some songs. A song does not need all of them.

What is the most common song structure?

Verse-chorus form: intro, verse, pre-chorus, chorus, verse, pre-chorus, chorus, bridge and chorus, with an optional outro.

How many bars are in a verse?

There is no fixed rule. In many styles sections are built in multiples of 4, 8 or 16 bars, so 8 or 16 is a safe place to start; rappers are generally given 16 bars for a guest verse.

What is the difference between a verse and a chorus?

Verses share their music but change their lyrics and tell the story; the chorus keeps the same lyrics, states the main idea and usually holds the hook.

What is a bridge in a song?

A section with different music and words that breaks up the repetition, usually after the second chorus and before the last one.