The same syncopation can be harmless or disruptive, depending on which beat or subdivision has already become the music’s governing motion.

In Koch’s examples 219 and 220, the written sixteenth-note tie is identical, but its effect is not. If quarter-note motion governs the passage, the smaller displacement is harmless. If eighth-note motion has been established, that subdivision must remain audible. The decisive issue is therefore the metrical level the listener has learned to expect.

When the smaller unit belongs to the established pulse, an accompanying voice must preserve it. In example 220, the bass has articulated each eighth note, so a tied sixteenth note cannot simply erase one of those attacks. The bass must mark the missing subdivision, not because syncopation is forbidden, but because metrical continuity and the passage’s characteristic motion depend on it.

A required bass note need not remain a single long value. Koch allows it to be divided into eighths or sixteenths, mixed with harmonic subsidiary notes, or linked by passing tones. What matters is that the attack on the required point remains clear. This separates structural articulation from ornament: diminution may enliven the texture, but it must not conceal the beat.

Once a pulse is firmly established, Koch allows something surprising: a beat may disappear from the score yet remain present in musical feeling.

At the junction of two complete phrases, an expected bass attack may sometimes be omitted. Koch’s example 223 shows that a brief metrical gap can be acceptable when the first phrase has clearly ended and no conflicting rhythm fills the space. The silence itself occupies the position, while the phrase boundary and the listener’s internal pulse make the missing unit intelligible.

Examples 224 and 225 sharpen the point. One version states the expected quarter-note attack; the other leaves it silent. The first may sound clearer, yet the second can still succeed because quarter-note motion has already become habitual. The listener mentally supplies the missing beat, provided that no contradictory rhythm weakens the established pattern.

Koch goes further in example 226, where metrical motion is interrupted for several measures for expressive reasons connected with the text. Such a break is not a mechanical mistake but a rhetorical gesture. The justification may involve poetic meaning, phrase completion, harmony, register, and expectation at once. Here musical expression exceeds what a single fixed rule can classify.

The real skill is not memorizing exceptions, but learning why a departure from regular motion strengthens one passage and damages another.

Longer interruptions work best where the form already prepares a division. In example 226, one extended phrase or block ends before another begins, and related openings help the listener recognize the new start. A formal boundary therefore supports the break. The same interruption inside an unfinished idea would be harder to justify because phrase completion and recurring gestures no longer clarify the larger design.

Because these exceptions resist exhaustive classification, Koch directs beginners toward good scores. Theory can identify beats, subdivisions, syncopations, and supporting voices, but repertoire teaches how masters adapt those principles. By playing, listening, and comparing passages, the student learns to feel silent articulations, judge metrical clarity, and recognize when a deviation strengthens rather than weakens the discourse.

Koch’s goal is not to replace rules with instinct. It is to build an instinct informed by theory, so that metrical movement can be heard even when it is ornamented, transferred, or briefly suspended. This prepares the next stage of his treatise: connecting melodic sections while preserving rhythmic intelligibility, phrase punctuation, and a convincing sense of musical motion.