The songs of popular music often use a traditional song form, or a song form that is derived from a traditional song forms. Sectional music forms are generally made up of one or more sections that may or may not be repeated with the same song. Typical song forms are derived from strophic form (AAA), 32-bar form (AABA), verse-chorus form (AB) and 12-bar blues form (AAB). Songs with a different melody and chord progression for each stanza, where there are no repeated sections (through composed form) are far less common in western popular music.

The primary focus of this article is to provide an explanation of how common song forms can be extended. This article builds upon the AAA, AABA, AB, ABC and AAB song forms, and upon compound song forms, explained in our other articles in this series. For simplicity some of the root musical forms or classifications of musical forms have only been referenced for completeness.

The meaning of some terms such as “verse” and “chorus” has changed over the years. For an explanation of the differences please refer to “Song Form Overview“.

Song Building Blocks

Popular music, in particular, often uses a number of common structural song parts.

The common building blocks are:

1. INTRODUCTION(INTRO)
2. VERSE
3. REFRAIN
4. PRE-CHORUS / RISE / CLIMB
5. CHORUS
6. BRIDGE
7. MIDDLE EIGHT
8. SOLO / INSTRUMENTAL BREAK
9. COLLISION
10. CODA / OUTRO
11. AD LIB (OFTEN IN CODA / OUTRO)

For details about these song building blocks please read our article, “Song Building Blocks”.

Extended Song Forms

Extended song forms build upon one of the root “whole song” song forms. Extended Song Forms add song sections to a base song form effectively extending the song form creating a new song. Sections added are sections already found in the song form. Examples of extended song forms would be:

1. AAAAA Song Form- which is an extension of AAA song form often called AAA Extended Song Form (nothing too complex here as there is only one section that is merely repeated as many times as needed)
2. AABABA Song Form – which extends AABA with a final bridge and verse section, also called AABA Extended Song Form. For further details about the sections involved in AABABA please refer to “AABA Song Form“.

Other Common Song Forms

There are also other types of song structures such as ABAB, ABAC, and ABCD, although these aren’t as commonly used as the other song forms.

ABAB Song Form

The sections of ABAB song form do not need to be 8 bars in length, but they usually are.

It normally begins with an A section of 8 bars, followed by an 8-bar B section, before repeating both the A and B sections again.

Listen to the song “Fly Me to the Moon” to hear a great example of ABAB song form. You will hear Frank Sinatra singing the beginning of the first A section as “Fly me to the moon” while he starts the first B section with “In other words, hold my hand”. The next A section then begins with “Fill my heart with song” while the final B section begins with “In other words, please be true”.

ABAC Song Form

The structure of this song is similar to that of the ABAB form. It begins with an A section of 8 bars, followed by a B section, also of 8 bars. ABAC then returns to the A section before finally a new section is introduced, the C section. The first few bars of the C section tend to be melodically similar to the B section before it becomes a new and different melody.

Movie themes and stage musicals often use ABAC song form. A good example of ABAC song form is “Moon River”, by Andy Williams. The C section starts melodically and lyrically similar to the earlier B section before the melody and lyrics go off in a new direction.

Through-Composed / ABCD Song Form

By being “through-composed”, also known as ABCD song form, it means that any musical ideas will not be repeated without introducing some significant variations to the extent that the melody would be considered as a new melody. Mainly used in art-song tradition songs in classical music, ABCD song form is highly uncommon in popular music. Some Progressive Rock music can be classed as “through composed” as there are many sections and the “progressive” label is indicative of the reliance on variation and evolution of both melody, rhythm, and even lyrics.

With ABCD song form, sections can vary in length, time signature, tempo, melody, harmony, and lyrics.

If you listen to Rodgers and Hammerstein’s “You’ll Never Walk Alone” you will hear what amounts to a new melody in each new section.