18th Century Polyphony
Harmonic Materials
By the year 1700, most of the features in art music that are referred to as Common Practice had been established. The triads and 7th chords built on all the scale degrees in both major and minor keys were part of the vocabulary. The melodic minor form, with raised 6th and 7th degrees ascending was supplanting the minor modes. The Phrygian cadence was still commonly used in minor keys.
Root movements, in addition to the most common downward 5th progression, were most often up a 2nd or down a 3rd. A sequence of chords expressed in Roman Numerals as I – vi – IV – V – I demonstrates these root movements. Progressions that do not move in these ways are referred to as retrogressions. The tonic and dominant pillars of the tonality could be approached by any chord, and the ii-I and the vi-V retrogressions were not uncommon. Chromatic harmonies such as the secondary dominant chord, the augmented 6th and the Neapolitan were also used. Voice-leading and chord doubling conventions were firmly established. The non-chord tone vocabulary was also well defined. This would be a good time to review the Guidelines for Voice-Leading and the Non-Chord Tones references in the Course Materials. The counterpoint of the day followed these practices, as did music in other textures. There was an increasing tendency among composers to write invertible counterpoint, in which any of the parts could be placed above or below the others.
Melodic and Rhythmic Materials
Melodies in the Baroque period were treated to extensive ornamentation in performance. Melodic movement was balanced between conjunct and disjunct, and leaps to dissonances in instrumental music became more common. With the basso continuo moving in longer note durations, the melodic lines were highly active and embellished. Most pieces employed a limited number of patterns and figures but achieved diversity through the application of variation techniques. These included sequencing, inversion, imitation, voice exchange, and other types of repetition with alteration. Composers have continued to use these standard developmental techniques to lend unity to their works, rather than introducing contrasting ideas. Analyzing polyphonic music involves identifying the variation technique applied by the composer to alter the original motives or phrases, and the tonal areas on which they are found.
Rhythmically, quadruple and triple meters were used consistently at various tempos. The harmonic rhythm, or rate of change, was not usually altered in a piece once it was established. It was not uncommon, however, for a section in 3/4 to be inserted in a piece that was predominantly in 4/4 time. Downbeats were accented in the bass parts, giving the upper parts a context for an upbeat, or anacrusis, approaching the primary accents. A popular device was the hemiola, which places accents every two beats in the context of a triple meter. The rhythmic nature of the movements in a Baroque suite were derived from the dance forms upon which they were based, as well as the tempos. In multimovement works, the overall structure was typically Fast-Slow-Fast-Slow.
Textures in Polyphony
There were four basic textures used in polyphonic music in the Baroque period. Works that employed a Continuo are the solo and trio sonatas, concerti, arias, and recitatives. These pieces included a bass instrument with the continuo improvised by a keyboard or lute. Works that were primarily Imitative are the canzonas, ricercars, canons, inventions, and fugues. They are characterized by virtually constant linear movement with motives and phrases shared between parts. Some pieces that do not fall into either of these types are called Free Counterpoint, such as toccatas, preludes, and dance suites. The term refers to works with a variety of mixed textures, and sections that are not exclusively contrapuntal. The last category consists of compositions that are based on a Cantus Firmus. These are the motets, ostinato variations, chorales, and chorale preludes.
The Chorale Prelude
The practice of writing choral preludes began with Johann Walter (1496-1570) and others during the Protestant Reformation of the 16th century, and various forms had evolved by the 18th century. In general, they are variations on chorale melodies that included florid counterpoint in the parts that surrounded the melody itself, or cantus firmus. They were typically written for organ, and Dietrich Buxtehude (1637-1707) was a prolific composer of both vocal and organ chorale settings, as well as toccatas and preludes. He was a primary influence on J. S. Bach.
One of J. S. Bach’s many contributions to the literature are his chorale harmonizations. They have been analyzed for centuries and provide a consistent representation of the common practice vocabulary. While Bach employed a wide variety of formats, most often a chorale prelude takes the melody and harmonic structure of a chorale and embroiders it with counterpoint in all but one voice, usually the highest part. Other parts maintain a dense imitative texture. A compilation of his organ works, the Orgelbüchlein, includes 46 chorale preludes along with other works. Three of these are linked in the Materials below. Examine them to find the original chorale melody, and analyze the contrapuntal techniques applied by Bach in creating the chorale preludes.