POLYPHONIC TEXTURE AND GENRES

Polyphony Polyphony (polyphonic texture) is an important texture in all historic style periods. Polyphony contains two or more active melodies. In contrast to homophony, emphasis is placed upon the interplay between lines rather than on a single melody or a stream of chord sounds. The interplay of contour, motives, continuity features, and rhythms are important factors in polyphonic texture.

Rhythmic Strata

Rhythmic stratification, also called layers, results when two or more voices move at different but closely related levels of rhythmic activity. One voice may contain mostly quarter notes while another contains eighth notes. This is somewhat like different parts of a machine moving at different but related speeds. Layering is an important feature of polyphonic texture.

Roles of Voices;

In polyphony, all the voices may be equally important—or one voice may be more prominent than the others. Voices may join in couplings or conversation-like exchanges, a polyphonic feature present in most of Bach's chorales.

Individual voices change roles in polyphony more frequently than in homophonic texture. These roles change periodically and systematically in canons, inventions, or fugues. The voices may share the same motive ideas and be closely related by content. Conversely, some or all of the voices may use motives that differ from those used in other voices. This causes greater independence among the voices.

The high voice is the principal melody in the next passage, the low voice a subordinate accompanying melody. The excerpt is polyphonic because a melody is accompanied by another. A quarter note rhythmic strata (layer) is established in the bass that provides a steady rhythmic background to the melody. The rhythms in the top line are more varied.

Example 1: March in D Major J. S. Bach




Counterpoint Counterpoint is the interaction of voices in polyphonic texture. Imitative counterpoint occurs if one voice repeats or mimics the patterns just stated in another voice. A canonic process occurs if the anwering voice or voices repeat the lead voice exactly. A composition based upon this process is a canon. Imitation is continuous throughout a canon. The next excerpt is the beginning of the fourth movement of a sonata. The violin is in canon with the top voice of the piano.

Example 2: Canon in Sonata for Violin and Piano César Franck





Imitation Intervals and Time Intervals One voice may imitate another at the same or different pitch level. The interval of imitation is the interval of transposition. If the the answering voice does not change level, imitation is "at the unison." The previous example was in canon at the octave.

The time interval measures the number of beats between the beginning of the original idea and the answer. Time intervals vary in length and sometimes change within a composition.

Both voices are of equal importance in the next example. One voice imitates the other in a canon-like pattern but imitation ceases two measure before the cadence. The first two measures are imitated in inversion. The lead voice is repeated at the perfect fifth, thus the interval of imitation is P5. The imitation occurs two beats later thus the time interval (delay) is two beats.

Example 3: Cantione no. 1 Orlando de Lassus







Discounting the middle voice, the next excerpt has the following features: a. the two essential voices (top and bottom) are of equal importance b. the two voices are independent in rhythm, contour, and content. c. the voices do not exchange roles. The middle voice strictly parallels the top voice at the interval of a P4, an example of organum. Perform the example with and without the middle voice and note the difference in effect.

Example 4: from Missa Sancti Jacobi Dufay

Communio


The next example has the following features: a. All voices are of equal importance b. All voices are independent in contour, rhythm, but NOT in content. Each voice    repeats ideas presented in the lead voice c. The roles of the voices change as each new voice enters in imitation of the    preceding voice. Each voice continues in free counterpoint after repeating three measures of the lead voice. Compare mm. 4-6 of the middle voice with mm. 6-8 of the bottom voice. The pattern is imitative but not canonic.

Example 5: from Missa Aeterna Christi Palestrina

Benedictus



Non-imitative Polyphony The next excerpt illustrates two-part, non-imitative polyphony because the ideas in one voice do not recur in the other. The texture is polyrhythmic instead of monorhythmic because the voices never use the same rhythm patterns at the same time. The contours move in opposition. The net result is two independent lines.

Example 6: Virelai Machaut






In the next excerpt, the two treble parts form one coupled voice while the bass provides a sixteenth note contrast. This produces two distinct rhythm layers. The contrast between the treble and bass voices is caused by differences in rhythm and contour.

Example 7: from Sonata da camera a tre,op. 4 Corelli

Allemanda, allegro


The next excerpt is four-part polyphony. Three of the four voices use similar motive material to establish a unity among these voices. Although these voices are related by motive content, the texture is non-imitative. The chorale tune (Jesu, meine Freude) is in the soprano voice. Contrast is supported by rhythmic strata, quarter notes in the tune in opposition to eighths and sixteenths in the other voices. The result is the polyphonic accompaniment of a melody.

Example 8: from the Little Organ Book Bach

Chorale Prelude; Jesu, meine Freude, BWV 610



Imitative Polyphony The next excerpt is two-part, imitative polyphony. One voice mimics the motive ideas of the other. The texture is polyrhythmic because two distinct rhythmic strata are present, one in eighth notes and the other in sixteenths. The roles of the voices alternate in a cyclical pattern. Bach called this kind of composition an invention, a fugue-like process that features the systematic recurrence of a thematic idea called a subject. The sixteenth note motive is the main thematic idea of this invention.

The eighth note motive is an accompaniment figure. All the material in the invention is derived from these two ideas.

The subject is stated in each voice. This is followed by a passage made up of figures derived from the first two measure. This procedure is repeated two more times in the composition (not shown here).

A complete invention is included in the applications at the end of this chapter. When analyzing this invention, note how the beginning of each section is defined by the recurrance of the subject.

Example 9: Invention No. 4 Bach







The next excerpt is three-part imitative polyphony. A three-measure melodic idea is repeated verbatim in the other voices. Once the idea is stated, each voice continues with an accompaniment pattern of nonimitative counterpoint. The process is canon-like but not a strict canon.

Example 10: Sanctus from Missa Aeterna Christi Palestrina




The Desprez excerpt is made up of two two-part canons, a double canon. The soprano and alto make up one canon and the tenor and bass the other. The voices in each canon are identified with Roman numerals.

Example 11: Baises moy Desprez




Harmony in Polyphony; Polyphonic texture can be reduced to a basic harmonic core, usually a monorhythmic chorale-like pattern . This is done by removing rhythmic ornamentation and noting underlying voice leading. As shown in the next excerpt, even two-part polyphony implies a harmonic core.

Example 12: March in D major J. S. Bach




As more voices are added, the impression of background chords becomes more complete This can be seen in the next two examples.

Example 13. I Gave Her Cakes Purcell



In the next example, the rhythm of the background harmony is less supportive of the meter. Use of more third relations in this progression softens the focus on tonic.

Example 14. Agnus Dei Palestrina




Texture Analysis;


Texture Variables; Prominent rhythmic and melodic ideas are heard as figure on ground. The performing medium and texture are elements of this ground, helping to establish an environment that influences the meaning of figure. Changes in this ground often support basic changes in the pattern and structure of a composition—the form of the composition. The textural map of a composition is an aspect of its form.

Variations in texture pattern contribute greatly to the form and mood of a composition. Composers and arrangers coordinate changes in texture with changes of key, mode, melodic pattern, continuity, rhythm, and harmonic background.

Texture factors contribute to the development of musical form. These factors are used as both constants and variables. When used as constants, textural patterns establish steady states that give a section of a composition its characteristic features.

When used as variables, changes in texture pattern create contrasts that stimulate the listener's attention. These contrast help to establish new sections in the form of the composition.

Case Study 1, Oculus no vidit (Orlandus Lassus) The short composition in the next example illustrates how a composer controls texture to shape a composition and sustain interest. Perform and listen to this composition while analyzing it. Refer to Appendix F for information on factors that affect textural pattern. Make a copy of the appendix to avoid page flipping.

Overview The composition is through-composed and each section starts with a new motive. Each section of this composition is marked by a letter in a box. The phrases within each section are marked by lower case letters. The interval of imitation is enclosed in parentheses. These intervals change during the course of the work. The ascending and descending P4 motive recur as parts of new thematic ideas (compare sections B and D).

The Latin text of this composition translates roughly into English as follows:

Eye hath not seen, nor ear heard, nor rose in man's heart, what God has prepared for them that love him.

The composer established a close tie between words and music. Each phrase of music corresponds to a clause in the text. Sections A and B each contain two clauses and thus two phrases of music. The remaining sections contain one phrase each . Section D2 is a repeat of section D1.

Perform and listen to this composition before attempting to analyze it. Look for a connection between musical patterns and word meanings, word rhythms, poetic form of the text. Does the close study of this composition help you to look at the composition with more interest and detail, to see and appreciate the ties between words and music? Does the depth to which you understand this composition affect the quality of your performance? Become familiar with the work before studying the comments that follow it. Perform and listen to the composition.

Example 15. Cantione No. 3 ( from Cantiones duarum vocum) Orlandus Lassus














Comments on Oculus non vidit
1. Unifying Constants    Register: Constant, limited to soprano and alto vocal ranges Density: two voices Sound Norm: Most beats and accents are reserved for consonant intervals. Dissonant intervals are used mostly as unaccented melodic links (i.e. passing tones, etc.). Dissonant intervals are rarely accented. Kind of Pattern: Imitative polyphony, polyrhythmic Relative Complexity: similar throughout the composition.

2. Texture Variables    Range/Spacing: is changeable because of the independent movement of the two voices. A change to open or closed spacing is used sometimes to set off a new section. Sound: Cadences at the end of each section are marked by dissonance, an ornamented suspension figure. The interval of imitation varies from section to section although imitation at the fifth is common. Location of Figure: Changes in leader/follower roles help to distinguish one section from another. The inverted imitation starting at bar 16 is distinctive. Rhythmic Interplay: Rhythmic dialogues, changes in rhythmic pace alternates between voices, pace increases before cadences.

3. Shaping Factors    a. New motives are used in each section. b. Extra emphasis is placed on the D section through repetition (D1, D2). c. Cadences feature special suspension motives that reinforce punctuation. Each cadence is preceded by an increase in pace. Imitation ceases at these points. Activity slows just before each cadence pitch, A, E, A, and D (all a perfect fifth apart!). d. Section C is the dramatic high point in the composition. Contours are in strong opposition, coinciding with the most rapid increasesin range and spacing in the composition. The alto voice moves a tenth in one bar at this point, a particularly dramatic gesture in comparison to the rest of the composition. This gesture occurs again near the close of section C.

4. Speculations About Word Painting
a. the word "oculus" (mm.1-3) is set to open notes, perhaps symbolizing open but blind eyes.
b. the word "aurus" (mm. 4-8) is set to active, ornate rhythms, perhaps suggesting the "hearing" of figure.
c. "cor hominis" is set to a change to triple meterand a close time interval in the imitation. This creates a "heart beat" pulse in the music.
d. "ascendit" is set in ascending lines. The "heart beat" rhythm continues in duple meter.

The Italian text relates to spurned love and translates roughly into English as follows: I die, weak from pain, And the one who could give me life, Alas, kills me and will not give me life. O sad fate, The one who could give me life, Alas, gives me death.

Only the setting of the first stanza is included here. In the complete work, the first stanza of the text occurs a second time at a new pitch level. The first and third lines of the second stanza (beginning with "O dolorosa") are repeated but the middle line is stated only once. The final line, "ahi, mi da morte" is repeated several times.

Texture patterns are related to key words in the text. Gesualdo singled out certain key words for special treatment. "Moro" (I die) was given a chromatic and slow monorhythmic setting. In contrast, "vita" (life) was given a diatonic, animated, polyrhythmic setting. "Ahi" ("alas," "oh," or "oi"), is repeated antiphonally, in sudden contrast to previous material, a dramatic gesture like pressing one's hand on the chest or forehead. During this period (early Baroque), composers routinely used descending chromatic lines to symbolize sorrow or death.

Perform and listen to this excerpt before attempting an analysis. What textural constants and variables did Gesualdo use when setting each individual line of the text? How does the setting of one line differ from the next?

Example 16. Moro, Lasso, al mio duolo (section 1, first stanza, mm. 1-22) Gesualdo

mm. 1-6 "Moro, lasso al mio duolo"
monorhythmic, chromatic, slow pace, minor, homophonic.

mm. 7-12 "e chi mi puo dar vita"
polyrhythmic, diatonic, lively, major, imitative.

mm. 13-22 "ahi, che m'ancide e non vuol darmi vita"
polyrhythmic changing to monorhythmic, chromatic, medium pace, imitative then chordal.

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Twentieth Century Polyphony-

Twentieth century composers also use polyphonic process, sometimes adopting baroque, renaissance, and medieval patterns and procedures. However, twentieth century polyphony differs from earlier literature in its use of dissonant intervals and new ways to relate thematic material.

Examples of Two-Part Polyphony in the Twentieth Century-

The next excerpt is a modern setting of an ancient chant. The chant is stated like a cantus firmus in the bass clef. Note the differences between the two parts in contour, rhythm, and interval continuity—and the kinds of harmonic intervals that occur on the beat, especially in m. 4.

Example 17: Engelkonzert from Mathis der Maler (1934) Paul Hindemith





The next excerpt is repetitive, essential to the effect of this passage. Although the range of each voice is limited, interest is sustained by the syncopated interplay between voices. Contours, although limited in range, move in opposition. The succession of intervals follows no pattern of tension and release, dissonant intervals are not resolved. Dissonance is a byproduct of the rhythmic offset between equally important voices.

Example 18: from Rite of Spring, Second Part, The Exalted Sacrifice (1913) Igor Stravinsky


As suggested by the title of the next excerpt, Bartok made the tritone an important feature of this composition. The composition is based upon two tetrachords, a tritone apart. The texture is imitative, but in inversion. Note the kind of intervals used on accents. The net effect is dissonant.

Example 19: Diminished Fifth,Vol. IV, Mikrokosmos (1926-1937) Bartok

mm = 110



The final example is the most recently written passage in this series of excerpts. Its two parts are independent in rhythm, contour, and content. Dissonant intervals are emphasized. How does the composer's choice and treatment of intervals prompt you to respond to the passage? How does this example differ from other examples? All twelve tones of the chromatic scale are employed in the first three measures.

Example 20: Duet Milton Babbitt





1. Terms

polyphony	polyphonic texture	canon
rhythmic strata	rhythmic layers	double canon
imitation interval	time interval	texture variables
non-imitative polyphony-	imitative polyphony-	texture constants
invention subject

Application, Analysis

Perform and listen to the composition before attempting an analysis. Perform and listening periodically during the analysis to check your findings. When completing the analysis, refer to appendix B (Guide to Analysis of Contour, Continuity, and Skeleton of Melody), C (Motives and Their Variants), D (Guide to Analysis of Motives, Phrases, Phrase Groups), and F (Guide to the Analysis of Musical Texture).

1. Two-Part Invention no. 1, J. S. Bach. The complete invention is included below. An analysis of the motives was started in Part 1. One motive was labeled "a/b" because it combines the rhythm of motive b with the first four notes of motive a. One can also conclude that all ideas are derived from motive a. Use this analysis as a guide when completing the analysis of motives used in the remainder of the work. Write a few paragraphs to explain and compare how the thematic material was used in Parts 1, 2 and 3 of the invention.



















Listen to recording of any or all of these composition, preferably with score in hand. This as an opportunity to practice score reading. Follow significant thematic material as it flows from voice to voice. At the same time, observe changing details in the texture.

Any two-part Invention (Bach),
Any prelude and fugue in the Well Tempered Clavier (J. S. Bach)
Two-part compositions in Mikrokosmos, especially Books 5 and 6 (Bela Bartok)
Any prelude and fugue in Ludis Tonalis (Paul Hindemith),
Hymn and Fuguing Tunes (Henry Cowell)
Rounds for String Orchestra (David Diamond)
Fugal passages from Metamorphisis on a theme by Carl Maria von Weber (Paul Hindemith)
Fugue from Young Person's Guide to the Orchestra (Benjamin Britten)
Dirge of Serenade for Tenor Horn and Strings (Benjamin Britten)
Music for Strings, Percussion, and Celeste, first movement. (Bela Bartok)
Music for Theatre (Aaron Copland)