Form is a general term that addresses the organization and ordering of the phrases and sections of a musical composition. At the level of an individual work, the study of form allows listeners to appreciate large-scale patterns, repetitions, and divergences from conventions and expectations. More broadly, form allows listeners to compare and contrast multiple works; this is an important aspect in developing an understanding of musical genres.
Form is often distinguished from “content,” where the latter term refers to the features unique to an individual work (melody, meaning expressed, etc.). In this regard, it is helpful to consider musical form by analogy to literary forms: Shakespeare’s sonnets share the same formal characteristics (scansion, rhyme scheme, etc.), but they differ in words, and thus in content. In the same way, hundreds of Blues songs share the same form (articulated by phrases and standard harmonic progressions), but express different content in terms of melody and lyrics. Form thus provides relatively stable background structures against which musical creation can occur.
Different forms have been favored at different times in the history of Western music. Much of the popular music currently protected by copyright uses forms that are relatively easy to grasp, especially when lyrics are involved. Most importantly, they tend to have easily recognizable parts that are common to many popular songs. These include the introduction, verse, chorus, instrumental solo section (often taking the same musical space as a verse). One of the most common forms is known simply as Verse-Chorus form, which is frequently arranged in the following way:
Verse 3 (Instruments only)
Chorus and fade
Musical forms then, like poetic and literary genres (sonnet, novel) are not copyrightable and no individual creator can monopolize the use of any of them.