First-species counterpoint is a traditional compositional exercise that teaches beginning musicians to consider how to start and end melodic lines, and most importantly, how to keep them independent of each other.

When writing in first species, follow these rules:

Begin on a perfect unison, fifth, or octave.

Both voices move at exactly the same rate and have no rhythmic variety (for example, all notes are whole notes).

Harmonically, the intervals between the two voices are all consonances.

Melodically, prefer stepwise motion and leap only occasionally. Melodic leaps of a tritone or seventh are forbidden.

Parallel perfect consonances are forbidden.

End with a perfect unison or octave.

This chapter presents additional guidelines that will help in writing a successful first-species counterpoint.

Counterpoint is the mediation of two or more musical lines into a meaningful and pleasing whole. In first-species counterpoint, we not only write a smooth melody that has its own integrity of shape, variety, and goal-directed motion, but we also write a second melody that contains these traits. Further, and most importantly, we combine these melodies to create a whole texture that is smooth, that exhibits variety and goal-oriented motion, and in which these melodies both maintain their independence and fuse together into consonant simultaneities (the general term for two or more notes sounding at the same time).

In first-species counterpoint, we begin with a cantus firmus (new or existing) and compose a single new line—called the counterpoint—above or below it. That new line contains one note for every note in the cantus: both the cantus firmus and the counterpoint will be all whole notes. Thus, first species is sometimes called "one-against-one" or 1:1 counterpoint.

The Counterpoint Line

In general, the counterpoint should follow the principles of writing a good cantus firmus discussed in the previous chapter, Introduction to Species Counterpoint. There are some minor differences, to be discussed below, but generally a first-species counterpoint should consist of two cantus-firmus-quality lines.

Example 1 shows the complete exercises of first-species counterpoint from Part I of Gradus ad Parnassum. Each example sees one of the cantus firmi we've already met combined with a new counterpoint line either above or below. We've annotated each one with the interval that the counterpoint line makes with the cantus firmus. For the complete examples from Gradus ad Parnassum as exercises, solutions, and annotations, see Gradus ad Parnassum Exercises.

Example 1. All first-species exercises from Gradus ad Parnassum.

Beginning and Ending

Beginning a first-species counterpoint

Note that each exercise in Example 1 begins with a perfect consonance. This creates a sense of stability at the opening of the line.

When writing a counterpoint above a cantus firmus, the first note of the counterpoint should be do (\hat1) or sol (\hat5) (a P1, P5, or P8 above the cantus).

When writing a counterpoint below a cantus firmus, the first note of the counterpoint must always be on the modal final, do (\hat1) (P1 or P8 below the cantus firmus). Beginning on sol (\hat5) would create a dissonant fourth; beginning on fa (\hat4) would create a P5 but confuse listeners about the tonal context, since fa–do (\hat4-\hat1) at the beginning of a piece is easily misheard as do–sol (\hat1-\hat5).

Ending a first-species counterpoint

The final note of the counterpoint must always be do (\hat1) (P1 or P8 above/below the cantus).

To approach this ending smoothly, with variety, and with strong goal orientation, always approach the final interval by contrary stepwise motion, as follows:

If the cantus ends re–do (\hat2-\hat1), the counterpoint’s final two pitches should be ti–do (\hat7-\hat1).

If the cantus ends ti–do (\hat7-\hat1), the counterpoint’s final two pitches should be re–do (\hat2-\hat1).

Thus, the penultimate bar will either be a third or a sixth between the two lines (Example 2). This ending formula is known as the clausula vera. The exercises in Example 1 each end with a clausula vera.

Example 2. Examples of the clausula vera.

Independence of the Lines

Like the cantus firmus, the counterpoint line should have a single climax. To maintain the independence of the lines and the smoothness of the entire passage (so no one moment is hyper-emphasized by a double climax), these climaxes should not coincide.penultimate

A single repeat/tie in the counterpoint is allowed, but try to avoid repeating at all. This promotes variety in the exercise, since there are so few notes to begin with.

Avoid voice crossing. Voice crossings diminish the independence of the lines and make them more difficult to distinguish by ear.

Avoid voice overlap, where one voice leaps past the previous note of the other voice. For example, if the upper part sings an E4, the lower part cannot sing an F4 in the following bar. This also helps maintain the independence of the lines.

Intervals and Motion

The interval between the cantus firmus and counterpoint at any moment should not exceed a perfect twelfth (octave plus fifth). In general, try to keep the two lines within an octave where possible, and only exceed a tenth in “emergencies” and only briefly (one or two notes). When the voices are too far apart, tonal fusion is diminished. Further, it can diminish performability, which, though not an essential principle of human cognition, is an important consideration for composers, and it has a direct effect on the smoothness, melodic integrity, and tonal fusion of what listeners hear during a performance.

In general, all harmonic consonances are allowed. However, unisons should only be used for the first and last intervals. Unisons are