0.5 Musical form  (Page 2/2)

Musical form is the wider perspective of a piece of music. It describes the layout of a composition as divided intosections, akin to the layout of a city divided into neighborhoods.

Musical works may be classified into two formal types: A and A/B. Compositions exist in a boundless variety of styles,instrumentation, length and content--all the factors that make them singular and personal. Yet, underlying thisindividuality, any musical work can be interpreted as either an A or A/B-form.

An A-form emphasizes continuity and prolongation . It flows, unbroken, from beginning to end. In a unified neighborhood, wander down anystreet and it will look very similar to any other. Similarly, in an A-form, the music has a recognizable consistency.

The other basic type is the A/B-form . Whereas A-forms emphasize continuity, A/B-forms emphasize contrast and diversity . A/B-forms are clearly broken up into sections, which differ in aurally immediate ways. Thesections are often punctuated by silences or resonant pauses, making them more clearly set off from one another. Here, youtravel among neighborhoods travels that are noticeably different from one another: The first might be a residentialneighborhood, with tree-lined streets and quiet cul-de-sacs. The next is an industrial neighborhood, with warehouses andsmoke-stacks.

The prime articulants of form are rhythm and texture . If the rhythm and texture remain constant, you will tend to perceive an A-form. If there is amarked change in rhythm or texture, you will tend to perceive a point of contrast--a boundary, from which you pass into anew neighborhood. This will indicate an A/B-form.

Listen to the following examples. What is the form of each?

Labeling the forms

It is conventional to give alphabetic labels to the sections of a composition: A, B, C, etc . If a section returns, its letter is repeated: for instance, "A-B-A"is a familiar layout in classical music.

As the unbroken form, A-forms come only in a single variety. They may be long or short, but they are always "A".

As the contrast form, A/B-forms come in a boundless array of possibilities. There may be recurring sections, unique ones,or any combination of both. For instance, a Rondo --a popular form in Classical music--consists of an alternation of a recurring section andothers that occur once each. It would be labelled A-B-A-C-A-D-A, etc . Many twentieth-century composers became fascinated with arch-forms: A-B-C-B-A.

An on-going form, with no recurrence whatsoever, is also possible: A-B-C-D-E... Any sequence of recurring and uniquesections may occur.

Conclusion

Understanding the layout of the city is crucial for exploring it: once you understand its topography, you know how to findits landmarks, where the places for recreation or business may lie. Similarly, determining the form of a piece will tell youa lot about it. If it is an A-form, your next focus will be on the work's main ideas, and how they are extended across theentire composition. If it is an A/B-form, your next investigations will be into the specific layout of sectionsand the nature of the contrasts.