Leap and recovery

A leap borrows energy the line must repay: after any large leap the melody turns back by step in the opposite direction. Two leaps the same way — or a leap left hanging at a phrase’s edge — outline arpeggios rather than melody and spend the voice’s range without cause. Small thirds move freely; the wider the leap, the firmer the debt, and the octave demands its stepwise answer immediately.

It is the single most reliable test of a melody: lines that sing — chant, chorale tunes, fugue subjects — honor it almost without exception, and lines that feel instrumental or aimless usually broke it. The rule also manages range: a leap answered by steps keeps the climax in reserve, while stacked leaps arrive at the top with nothing left. In florid counterpoint and free composition alike, it is the difference between a gesture and a spasm.

• Following a large leap with another leap in the same direction, outlining a chord instead of a line.
• Recovering by step in the same direction as the leap, which extends the spree rather than repaying it.
• Leaping to the climax and away again, so the high point is touched rather than earned.
• Ending a phrase on an unrecovered leap, which leaves the line’s energy hanging past the punctuation.

• Johann Joseph Fux, Gradus ad Parnassum (1725), Liber secundus, the rules of melodic motion — The dialogue’s melodic discipline: after the leap, the turn by step.
• Luigi Cherubini, Cours de contrepoint et de fugue (1835), The preliminary rules (the conduct of the melody) — The same compensation rule in the Conservatoire course.