Disjunct

Steps and leaps

Every melody consists of note sequences, and each sequence is either a step (a second up or down) or a leap (a larger interval). Teaching calls a line conjunct if steps predominate and disjunct if leaps predominate. The two examples below show the difference within the same frame: the same time signature, the same closing note (C), but a quite different movement of sound.

How to recognise a disjunct line

Disjunct melodies often follow the notes of a triad. That explains why fanfares, signal calls and many horn themes sound as they do: on wind instruments without valves the reachable notes lie far apart, the melody leaps of its own accord. The building block Melody describes the weighting: most catchy melodies move mainly by step, and the single leap gains its effect precisely by being the exception. Disjunct lines are thus a deliberate counter-colour, not a normal form. Bass voices too like to move disjunctly, for example from root to fifth and back.

For singers large leaps are harder to hit than steps, because the ear must know the target note beforehand. That is why, after a large leap, textbooks of melody writing often balance it with a step in the opposite direction. That is a habit of voice leading, not a fixed rule.

In older tetrachord teaching “disjunct” has a second meaning: two groups of four notes are joined disjunctly if a whole tone lies between them, as with C–F and G–C in the major scale. The example is on the page conjunct.

Common mistakes

• Pigeonholing every melody: almost all melodies mix both. “Disjunct” or “conjunct” describes what predominates.
• Confusing disjunct with “jumpy in rhythm”: what is meant is the pitches, not the note values.
• Taking thirds for steps: a step is a second. The third already counts as a leap.