Heterophonic texture consists of simultaneous modifications of the same
musical (melodic) material. In other words, it is two or more equally active
lines sharing the same (or virtually identical) material. This type of texture
is rare in Western commonpractice music.
Monophonic texture simply refers to a single melodic line. It is fairly
rare in Western common practice music; Gregorian and other chants are the
best known examples.
Generally speaking, polyphonic texture refers to two or more independent
voices of equal structural importance. There are at least two broad categories
of polyphony: imitative and non-imitative.
I. Imitative polyphony
Imitative polyphony consists of two or more independent voices which "converse" with statements of an identical or very similar musical idea. The "musical idea" is often a motive, though it may be something longer, too. The imitation must be identical or very similar to the original ideaat the very least, the rhythm and the pitch shape are retained.
Once you've determined that the texture is imitative polyphony, it's possible to go into more detail, analyzing such things as how strict the imitation is, the pitch interval of imitation (how far apart the parts are intervallically), and the time interval of imitation (the number of beats which elapse between the original statement and the imitation). The opening of J.S. Bach's Invention in C Major, BWV 772, is a good example of strict imitation at the octave at the time interval of two beats:
It's no coincidence that the example above is by Bach--imitative polyphony was most prevalent in the Renaissance and especially Baroque periods, culminating in the fugue.
When strict imitation carries on for a lengthy time periodsay, an entire section or piecethen you are dealing with a canon of some kind.
See the contrapuntal works on pp. 434-463 of Music Sources for further examples.
II. Non-imitative polyphony (sometimes called give and take).
Non-imitative polyphony consists of two or more independent voices which "converse," but with different musical ideas. This sometimes involves the same rhythmic motive but different pitch shapes. The opening of Bach's Adagio in C Minor is a good example:
Generally speaking, homophonic texture consists of one prominent line and
one or more subordinate parts. There are at least two broad categories of
homophony: chorale texture and melody and accompaniment.
I. Chorale texture
Chorale texture usually involves a note-against-note
(also called homorhythmic or 1:1) relationship between the voices. Despite
this relationship, one might still locate a melodyoften it's in the top
voice. The examples below (gratefully borrowed from Dr. Mary Arlin) show
a simple harmonic phrase and then several types of chorale settings based
on these harmonies. Chorale settings were especially prominent in the Baroque
period.
a. Chordal setting
b. For instruments: brass, strings
c. Vocal setting, motet style
d. Chorale, baroque style
Melody and accompaniment is the most familiar of all types of texture. Piano works, vocal literature, dances, and many other genres include a primary melody and a subordinate accompaniment which supports it. Melody and accompaniment texture is used in all musical periods and was especially prominent in the Classic and Romantic eras. Most of the passages analyzed in this course have a melody and accompaniment texture.
An initial consideration is the location of the melody in relation to the accompaniment. Is it above the accompaniment (often the case), does it fall in the middle of the accompaniment, or is the melody below the accompaniment?
A related term is textural inversion, which simply means that the part which had the melody takes over the accompaniment and vice versa. The simplest example: envision a piano piece in which the right hand has the melody and the left has the accompaniment. At the point where the hands switch roles, textural inversion has occurred.
Once you have identified where the melody is, it is important to identify what type of accompaniment is used. In a very general way, one might characterize accompaniments as involving block chords or as involving broken chords of some kind.
The following examples are a series of variations on the opening of a familiar tune. As you can see, the melody (and its location) and harmony are not varied; what's changed (and thus featured) are the types of accompaniment.
A. Accompaniments involving some sort of block chords
1. Melody with a sustained chord accompaniment: this texture is the simplest and clearest, yet it does not have a great deal of rhythmic interest.
2. Melody with a repeated chord accompaniment: the texture is activated a bit by the rearticulation of the accompanimental chords. This appears to be chorale-like, though there is clearly a prominent melody and subordinate harmonic support.
3. Melody with an accompaniment best characterized
as rhythmic punctuation: here, the accompanimental chords are interjected
as punctuations on the second beat of each measure.
B. Accompaniments involving some sort of broken chords
Most accompaniments involve a "spreading
out" or projection through time of the various chord members. This
breaking-up of the chords lightens the texture and gives the music more
forward direction or motion; however, the harmony and even the voice leading
need not be altered.
1. Melody with a broken chord accompaniment.
2. Melody with an arpeggiated accompaniment (note the arpeggiation of complete chords).
3. Melody with Alberti bass accompaniment: this is a very specific type of accompaniment in which the chords are broken up into a distinctive contour pattern. Stereotypical of Classic period pieces (especially for keyboard); otherwise, a relatively rare texture type.
4. Melody with an accompaniment which includes ornamental tones: here, neighbor tones are added to the otherwise consonant underlying structure.
5. Melody with bass-afterbeat accompaniment: this example shows several different types which might best be characterized as "boom-chick-chick-chick," "boom-chick," and (in the final two measures) "boom-chick-chick." The texture in last two measures is sometimes called melody with a waltz accompaniment.