Imagine that you are driving through a foreign city for the first time. Building after building catches your eye. You circle past a monument, then a fountain. Restaurant, hotel, shops fly past. Trying to absorb and remember all of these landmarks quickly becomes tiring. Was the town square before or after the park? What was that shop you spotted? If you don't speak the language, an extra anxiety sets in. You try to decipher the street signs, negotiate the traffic. By the time you arrive at the hotel, you fall on your bed, exhausted.

Similarly, it is easy to get lost in the moment-to-moment progress of a piece of music: There are often too many details to remember, too many implications to contemplate. If the work is particularly dynamic, you may become overwhelmed with its rapid progress. If the musical language is unfamiliar, even one poorly understood sound may throw you into confusion.

The path to informed listening begins with a grasp of the whole composition. There are tremendous advantages to beginning with a commanding perspective: While details tend to pass by very quickly; the overall trajectory of the music unfolds more gradually, giving us more time to consider it. The significance of an individual gesture is often clearer when we relate it to the work's overall destiny. And, while the immediate sounds are bristling with personality and may be difficult to grasp, the larger structure is often easier to hear accurately.

In your next visit to a new city, your exploration begins with a more patient and disciplined approach: You start with an overview of the neighborhoods. At first, you don't need to speak the language; nor is there the pressure to remember facades or street-names. First, you notice that you are traversing the old town, where the buildings are closely packed together and the streets narrow and winding. Then, you pass into the modern section, with sleek high-rises, set apart along wider thoroughfares. Later, you may revisit the old town on foot, discovering quiet alleys and ancient monuments. But, for now, you content yourself with a general sense of the city's layout: How large is the old town compared to the new? How much variety of architecture characterizes each neighborhood?

We will approach listening to music in a similar way. First, we will develop a sense of its entire expanse. Then, we will gradually sink into the details with a stronger sense of their relevance.

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

There are only two basic formal types: A and A/B.

An A-form emphasizes continuity and prolongation. It flows, unbroken, from beginning to end. In a unified neighborhood, walk down any street and it looks highly similar to any other. Similarly, in an A-form, different passages of the music will sound very similar.

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. The sections are often punctuated by silences or resonant pauses, making them more clearly set off from one another. Here, the traveler travels among neighborhoods that are noticeably different from one another: The first might be tree-lined, with the houses spaced luxuriously far apart, while the next is more urban, with the dwellings clustered close together.

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

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

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.

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

On the other, A/B-forms come in an endless array of possibilities. There may be recurring sections, unique ones, or any combination of both. For instance, a Classical Rondo consists of an alternation of recurring and unique sections: A-B-A-C-A-D-A, etc.

Other possibilities include A-B-C-D-E...--in which no section is repeated--and arch forms, such as A-B-C-B-A. Any combination of recurring and unique sections is possible.

Understanding the layout of the city is crucial for exploring it: once you understand its topography, you know how to find its landmarks, where the places for recreation or business may lie. Similarly, determining the form of a piece will tell you a 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 the entire composition. If it is an A/B-form, your next investigations will be into the specific layout of sections and the nature of the contrasts.

Before we continue with more detailed analyses of A- and A/B-forms, we have other large-scale features to discuss. Thus far, we have considered spatial metaphors for music. However, a musical performance is not a static structure: It progresses through time. Therefore, a complete reckoning of musical form requires a dynamic component--one that is time-dependent. You are free to enter a city from the north or south and move about at will. However, there is only one way to enter a musical performance--from the beginning--and one way to exit--the end. It is music's time-directed nature that enables it to be dramatic.