SUNY-Fredonia School of Music

Writing A Cantus Firmus

1. The melodies are composed solely of whole notes; this simplification of note values encourages a focus on melody alone.

2. No chromatic half steps appear; the only accidentals are those necessary to create a leading tone or to avoid an augmented second in approaching the leading tone from below. Thus, the "harmonic minor" scale will not be used because of the augmented second that exists between scale degrees 6 and 7.

3. Occasionally a note may be repeated, but rarely more than once.

4. Only melodic intervals easy to sing are used: no leaps of augmented or diminished intervals, no leaps larger than a P5 and minor 6th except for the octave. Minor sixths occur only very occasionally and always in ascending–never descending–motion. Major sixths are entirely absent.

5. All melodies end on the tonic of the key. This tonic is approached by scale degree 2 or 7 only. All melodies also begin on the tonic; although the first note is usually the first degree of the scale, this is not a strict rule. If not the tonic, the first note will probably be the dominant.

6. Whenever a leap occurs, either the note immediately preceding or the note immediately following should move in the opposite direction to the leap itself. That is, leaps must be either approached or left by motion in the opposite direction so that the leap is "filled in." Although leaps may be both approached and left by movement in the opposite direction, this contour is not a requirement except in the case of large leaps–that is, the minor sixth ascending and the octave, ascending or descending.

The guide for leaps of a 3d, 4th, or 5th may be put this way: when a leap occurs, it is either at the bottom of a line or at the top, not somewhere in the middle.

7. The ascending minor 6th and the ascending or descending octave are considered very large leaps. Therefore, for the sake of balance in the line, the notes both preceding and following must lie within the gap produced by these leaps.

8. Occasionally one may write two successive leaps in the same direction. In this case, the double leap must be preceded and followed by a motion in the opposite direction. Moreover, the double leap itself must outline a major or minor triad (not diminished or augmented). Or the two leaps may outline an octave: a P5 as the lower leap, and a P4 as the upper.

9. A high or low note should not be isolated by register from the other notes, but is always incorporated into the line by means of notes a step or two away.