Counterpoint Lession 12: further rhythmic diminution; Three voice chorale prelude

further rhythmic diminution;  Three voice chorale prelude

Part I - Further Rhythmic Diminution
Here, it is possible to have 3:1, 4:1, and even up to 6:1 rhythmic diminutions.  Often this takes the form of eighth or sixteenth notes against a dotted half, or half note.

Part II - Three-voice Chorale Preludes
Organ chorale preludes are often in four voices, although some have only three.  Most often the highest voice is the cantus, playing the melody.  And the lowest voice is a diminished note value of the cantus (usually twice as long)  meaning that the lowest voice is the exact same as the cantus but playing it at a longer note value. 
The inner voice of the chorale prelude uses imitation and diminution to provide counterpoint to the other two voices.   
Here is a three voice chorale prelude by Johann Kuhnau.  Listen for the entrance of each voice.  And notice that the lowest voice is hust an elongated version of the cantus.

Counterpoint Lession 11: Introduction to three-voice texture

 Introduction to three-voice texture

Part I - Note Against Note with Consonance Only

With three voice texture, one can have full chords (root, third, and fifth).  The rules of voice leading were followed meticulously during the Baroque era.  Rarely does one see irregular doubling, or even non-harmonic chords. 

Remember that when in the Baroque era a piece was in a minor mode, the final chord of the piece would be Major.  This is because of the temperament system used in the Baroque era.  It was about this time that all instruments were being tuned to the same standard.  In three note texture, rarely were there dissonances. 

Here we will look at three voice note-against-note texture and simple diminution.  All of the voice leading practices studied in theory apply here. To review, avoid doubling altered tones and the leading tone

Part II - elaboration in three voices

It is possible to elaborate up to two voices at a time in three voice texture.  Baroque composers use many of the non-harmonic tones discussed in the theory lessons on non-harmonic tones.  Most common by far though is the pedal tone.  This is because the pipe organ was beginning to gain popularity among composers.  Most of the time, the pattern is 2:1, 3:1, and even 4:1.  Rarely does one see higher than 4:1 in three voice texture.  

Good news!  I will have my computer back soon!  Then I can post the rest of the theory lessons.

Counterpoint Lession 10: The two part canon and invention

The two part canon and invention

Part I -  Two-part canon
As mentioned in earlier lessons from  Form and analysis, Canon in D by Pachalbel is NOT a canon because it does not follow the structure of canon form.  Canon  follows strict rules of imitation.  It stretches beyond restatement of the theme in a second voice.  The leading voice of a canon is called the dux, and the following voice the comes.  In two voice canon, the intervals of imitation are usually Perfect (unisons, 4ths, 5ths, and octaves). 

Here, is an example of canon in Corelli's Sonata No.7 in d minor.
notice that the dux enters at the octave.

part II - The two-part Invention
J.S. Bach wrote all of his inventions to be used for teaching pieces.  Inventions are written in canon form, with a dux, and a comes as the two voices.  The invention uses sequences to modulate between EPISODES (points where the theme returns in a different tonal center.  A typical invention will have four or five episodes before modulating back to the tonic before the final cadence.

Here is a Bach two-part invention, notice the use of sequences to modulate between episodes.

Counterpoint Lession 9: Real imitation and double counterpoint

 Real imitation and double counterpoint

Part I - Real imitation at the Octave and Fifth
Counterpoint at the Octave and fifth is just as the name suggests.  the first voice  states the theme, and the second voice imitates that same melody at either a fifth or octave away from the first melody.  Here is the first page of Bach's Two-part Invention in C.

Notice that the second voice imitates the cantus at  the octave.  The first voice begins on C, as does the second.  This is by far the most common form of counterpoint.  Of course, Imitation at the fifth does exist.  This is exemplified in Bach's Two-Part Invention in G
Here is the first page of the piece. 

Notice that the counterpointing voice imitates the cantus at the fifth.  The first voice begins on G, and the second on D. 

Part II - Double Counterpoint at the Octave
It is possible to have two voices imitate each other at the octave while a third voice imitates at the fifth or sixth.  This is known at double counterpoint.

Counterpoint Lession 8: further Diminution techniques in two voice texture

Further Diminution Techniques in two Voice Texture

Part I - sequences

As a Baroque technique, the sequence plays a huge part in counterpoint.  It is by definition one-voice imitation.  Observe the soprano voice in this figure, notice that it has the ascending eighth note figure.  This is known as a sequence.

Fig.1 Sequence

Notice that the first note of each group of eighth notes ascends by step.  This is the simplest example of a sequence.  further elaboration can be added, of course.  

Part II - Figuration Preludes

There are instances of further diminution where one voice outlines the chords of the the other voices, either by arpeggios, or other techniques.  the figure of: root - third - fifth - root is a good example of sequencing, because one voice will play root - third - fifth - root on each chord of the progression.  Doing so is known as a Figuration Prelude.

Here is the Bach Prelude in C BWV 924. it demonstrates arpeggiation in the counterpointing voice.