Contrapuntal Genres

Contrapuntal Genres

Part I - Imitation
Imitation is one of the most characteristic techniques of contrapuntal genres.  In music, imitation refers to repeating material in another voice or part at different times.  it is widely used when elaborating musical ideas.
 
Part II - Canon
The canon is one of the oldest forms of imitation techniques in music.  There are two distinct types of canon, Leader and follower, and Round.
  
Leader and Follower
This is where one voice will state the theme and the subsequent voices will state the theme as well while the voices that have already entered will provide accompaniment. 

Round
A round is the simplest type of canon.  A round is a melody sung by voices beginning at different times.  A common example is "Row row row your boat."

Mirror canon
This is where the theme is sung in melodic inversion by each of the followers. 

Retrograde canon
This is where the theme is sung forward and backward simultaneously.  There is no leader and followers.

Mensuration canon
Where one of the followers performs the canon melody in augmentation or diminution. 

Part III - Inventions
A genre unique to Bach's oeuvre is the invention for keyboard.  These collections are teaching manuals in which melodies are "invented" and elaborated by various contrapuntal techniques.  Here the melody is called the "subject"  and all other voices are called the "counter subject." 

Part IV -  Fugue
This will be an introduction to fugues.  We will discuss fugues more in depth in the lessons dealing specifically with counterpoint.  Originally the term fugue was used to describe thirteenth century pieces where voices sung in canonic imitation accompanied by a third voice. 

Subjects and answers
A fugue typically begins with an unaccompanied statement of the theme called the "subject."  Fugue subjects very widely in length from one measure to up to ten measures.  The subsequent entries of the subject will be accompanied by the "counter subject" in the voice that just finished the subject.  Once the subject and counter subject have finished playing, a third voice can enter and play the subject.  a general outline of a fugue looks like this:

Fig.1 Fugue outline

Following all of the entries of the subject and counter subject, there will be "episodes"  of varriation based on the subject in a variety of keys.  After all of the episodes, there will be a closing section where the subject is restated in its entirety in the tonic before a short coda.