Theoretical Aspects Of Counterpoint

Counterpoint can be defined as the combination of different melodic lines in a composition. Good counterpoint requires both a logical harmonic relationship between the lines as well as a degree of individuality and independences within the lines. Theorists have emphasized the vertical aspects of species counterpoint by defining the certain note combinations that are dissonances and consonances and prescribing where both should occur in both strong and weak beats. To contrast this, many great composers have shown more interest in and usage of the horizontal aspects such as the specific movement of the individual melodic lines and relationships of design and texture, as well as the balance between the horizontal and vertical forces that exist

Although rhythmic independence is not used in the first species, other types of independence can be used and these include directional independence. This may include the use of contrary motion (wherein the voices move in the opposite direction of each other); similar motion (wherein the voices move in the same direction); and parallel motion (wherein the voices remain apart in the same interval distances, as long as they are a third, sixth or tenth apart as well as no more than three repetitions of the same interval straight after each other). The use of parallel perfect consonances such as unison, perfect fifths, octaves and twelfths are not allowed to be used. (Krebs,

In addition to the other types of independence mentioned in first species, second species also has rhythmic independence. The contrapuntal line moves in a half-note pulse against the whole note pulse of the cantus firmus. One may begin by using a minim rest or by using a minim on the downbeat. One may end with two semibreves on scales degrees 7-8 or with two minims followed by a semibreve in the last bar. Besides for these rules, no other rhythms may be used, and ties are not used in second species. It is important to look out for parallel fifths and octaves. Adjacent parallels must be avoided, especially those on strong beats as these are audible due to the fact that there is only one unaccented note between them. Adjacent parallels on weak beats are allowed as they are not audible. (Krebs,