Harvey G. Cohen's stimulating article, "Music in the History Classroom" (Perspectives, December 2005), focused on song lyrics and the social and political importance of the composers and performers in U.S. history. The music itself, however, deserves attention, and can effectively be used in the classroom, especially in teaching Western Civilization courses. Though music is a highly abstract artistic medium, it still reflects its time and context. The development of Western classical music illustrates changes in society and intellectual life in unusual and illuminating ways that can usefully be explored in the history classroom.

Many historians (and students) do not have the background to understand and explain different musical styles. By reading one of the many introductory music texts, and then listening to a piece while following the musical score, ideally with a colleague from the music department, any historian can learn enough to communicate the crucial points. It is best to begin with Western music because it has all of the components necessary to understand other musical systems. The most important components are tonality, harmony and counterpoint, and form.

Tonality refers to the characteristic of music being in a particular "key," based on the 12-note scale that one finds on the piano. Western music expresses tonality through harmony and counterpoint.

Harmony is the system of consonances and dissonances in Western music, which derive from the acoustic structure of the overtone series. Counterpoint, or polyphony, is the use of multiple voices in Western music, ranging from independent melodic lines in orchestral music to melody and chords in popular songs.

Form is the relationship between the sections of a composition, and represents the peak of compositional achievement in Western music. The most important form in Western art music is the sonata, which was developed during the 18th century and is the basis for virtually all of the symphonies, chamber music, and other genres in the literature.

Western music did not begin with these components: they evolved over a thousand years in a process that corresponded to major shifts in Western intellectual history. In a survey course I use music to illustrate three of these shifts: the creation of tonality in the Renaissance and of the sonata in the Enlightenment, and the turn from tonality around 1900.

The Renaissance, as an intellectual movement, involved a return to the past. In music, however, it brought something very new. To show this, I play and explain a series of excerpts. I begin with the original Western music, which was monophonic, or consisting only of a single melody: Gregorian chant and secular music such as a troubadour song.

Then we hear the beginning of the new approach: Organum. In this music, composers—and we have some of the first identified composers in history with this development—used Gregorian chant as the basis and wrote new melodies to be sung above and below the chant at the same time, thereby creating the first counterpoint and harmony. This music (several recordings of which are available) is quite unusual and interesting, especially because this is where Western polyphony began, and virtually all Western music—classical, jazz, or rock—is polyphonic, with at least a melody and accompaniment.

Then the class hears a few examples of medieval music. Later composers began writing independent pieces—called "motets"—as settings of sacred and secular texts. Those of the 14th-century composer Guillaume de Machaut are good examples. One should listen to this music not only for its lyrical melodies but especially for its unusual harmonies. These composers did not have our sense of dissonance, but composers in Northern Europe in the late 14th–early 15th centuries tried to develop a different, smoother style, which culminated in the works of the first genuinely tonal composers, such as Josquin Despres. Just playing passages of 30 seconds from each of these composers can get this across. The smooth, consonant quality of Renaissance music derived from rules that these composers devised in writing counterpoint that student composers still study today.

The parallels between music and broader trends in Western history are often extremely suggestive. The breakthrough to consonant tonality was simultaneous with the development of one-point perspective in Renaissance art, and both tonality and perspective became "common practice" in their respective arts and remained so into the early 20th century. In a larger sense, the development of tonality corresponds to the humanists' rejection of medieval thought patterns.

The second turning point was the development of the sonata form in the 18th century. Here one can begin with a typical baroque composition such as an aria from Handel's Messiah. These pieces follow highly flexible forms, but always have a theme that recurs, and the composers use that recurrence for dramatic or emotional effect. The breakthrough to the sonata form was made by the early classical composers, especially Haydn and Mozart.

I explain to the class that the sonata was not a rigid form but rather a principle or template, a way in which composers would present and "develop" a series of musical themes in a manner that involved a movement away from and back to the original key. A typical sonata has three parts: (1) an exposition that presents themes (melodies and accompaniments); (2) a development in which the composer elaborates, combines, and alters these themes; and (3) a recapitulation that returns to the themes as in the exposition. The crucial aspect of this structure is the harmony. The exposition ordinarily introduces two main themes: the first is in the key of the sonata, but the second is in a different but related key; when these themes are brought back in the recapitulation, the second theme usually returns in the key of the sonata. Composers used this return to great effect: some of the most dramatic points in a Mozart opera ensemble (which are often in sonata form) are articulated by the music's return to the original key. Composers varied their articulation of every component of this form, making it extremely flexible and widely used: pieces ranging from a brief slow movement to an hour-long Strauss tone-poem are all sonatas.

To illustrate this principle it is sufficient to play one brief sonata piece all the way through; any short sonata by Haydn or Mozart will work, but the instructor must understand the piece and point out the sections while students listen.

Finally I contrast the classical style with the romantic, by playing something very emotional; a historian would of course prefer to use Chopin's "Revolutionary Étude" (op. 10 no. 12). The contrast between the simple, clear, highly structured, "rational" Haydn or Mozart, and the lush, dramatic, and formally vague Chopin piece (although it is also a sonata!) expresses vividly the contrast between the rationalism of the Enlightenment and the romantic social movements of the early 19th century. Chopin's étude was an expression of the romantic because it commemorated the 1831 Polish revolution.

The third shift, which instructors and students will find especially interesting, is the (apparently temporary) dissolution of tonality in the early 20th century. I begin by contrasting the work of a more conservative composer, Brahms's Handel variations, which exemplifies his adherence to classical forms, with Wagner's prelude to the opera Tristan und Isolde, which exemplifies the work of composers who experimented with tonality and form. The prelude's opening chord, the so-called Tristan chord, influenced many different composers for decades, despite Wagner's own German nationalist orientation.

Once students have a sense of late-romantic styles, one can illustrate some of the directions that music took. One is "Impressionist" music; for this the instructor could play Debussy's piano prelude "Voiles" to demonstrate the musical vocabulary of Impressionism. The resonances between this music and the paintings of such artists as Monet resemble those between Renaissance music and art in the 15th century.

Atonal music is another new development, and to illustrate this shift, I use excerpts from Schoenberg's Five Pieces for Orchestra or his string trio. Students can hear very clearly how different this music is from everything that came before. Atonal music was the standard for composers in American music schools for decades in the 20th century. This extreme musical modernism parallels the non-representational art of such expressionist painters as Kandinsky, who was influenced by Schoenberg.

Yet another direction was neoclassicism, a general term for composers who reacted against romanticism by reviving musical genres and styles from the 18th century or earlier, but with modernist harmonies and melodies. A famous example among this very diverse group would be Stravinsky, who began as an extreme modernist in his great ballets (Firebird, Petrushka, Rite of Spring), but then turned to baroque and classical forms. I usually play the beginning of The Rite of Spring to end these musical examples.

The parallels between music and other cultural and historical trends are less discernible in the 20th century than in the earlier cases. Still, I believe it is at least possible to hear in this music a reflection of the disintegration of Europe's secure bourgeois world under the impact of the Great War, revolution, fascism, and depression. If watching Ginger Rogers and Fred Astaire dance to Gershwin in 1935 distracted the audience from the dreary world outside, listening to Schoenberg or Stravinsky at the same time in a sense reflected that world.

This is not to minimize the value of popular music as a reflection of historical developments. Harvey Cohen's article suggested examples of this in the American context, and much can be done with European popular music as well. Similarly, non-Western music can also be used, not only to compare and contrast it with Western music, but also to explore connections between music and social history. That topic, however, is the theme of another opus.

—Mark Tauger is associate professor of history at West Virginia University. He would like to thank John Crotty, Mary Ferer, Gordon Nunn, and Chris Wilkinson of the College of Creative Arts at West Virginia University for helpful consultations.