The question of narrative or coherence rules above the level of the phrase

The majority of our focus thus far has been on musical utterances that have a temporal duration roughly equal to that of sentences, given physical restraints such as working memory. It was mentioned that the principles in operation at the level of the phrase cannot be assumed to be the same principles that govern larger structures. That is, it cannot be assumed that phrase-relevant rules are simply reapplied at higher hierarchical levels to handle larger musical structures. This is analogous to the idea that grammatical rules work on the level of sentences, but do not apply to entire paragraphs (groups of sentences). The principal reason why this is not possible for the case of music is because the phrase-relevant rules are derived from localised perceptive principles that are not in operation over longer periods of time. What we should now consider is the idea that there is a distinct set of principles operating at these higher hierarchical levels, ignoring for now the precise circumstances under which these higher-level rules come into effect. This is similar to the idea of some sort of set of principles governing the understanding of the logical course of argument in a group of sentences.

In the case of music, let us refer to this possible set of rules as narrative or coherence rules.118 These are the sorts of principles that govern how phrases themselves follow one another, how several phrases combine to form a recognisable section of a piece, all the way up to the level of the piece as a whole. What should be immediately apparent is that these principles – if they can be said to exist – are of a far weaker variety than the perceptive principles operating at the level of the phrase. They should be thought of as analogous to the sorts of guiding principles for constructing arguments in language, as if there was some sort of implication of logic guiding the manner in which certain arguments are made. This point is illustrated by

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‘Coherence’ is chosen after ‘discourse coherence’ (Patel, 2008a:335-342; Kehler, 2002). I have added ‘narrative’, as ‘coherence’ is already a music-theoretical concept regarding thematic material in musical pieces. However, ‘narrative’ has also been a concept used to describe the course of musical pieces within the New Musicology paradigm (see, for instance, Almén, 2008). The usage here has only a superficial similarity to that found in ‘narratological’ studies in New Musicology.

Patel (2008a:335-342), in a discussion on ‘discourse coherence’, drawing upon the work of Kehler (2002).119 Consider the following examples (from Patel, a8:335):

1. The father saw his son pick up his toy chainsaw. Seashells are often shiny on the inside. John likes peas.

2. The father saw his son pick up his toy chainsaw. The boy pretended to cut down a tree, but didn’t touch the delicate flowers growing in the garden. Mom was pleased.

The sentences in the two examples quoted above are grammatically well-formed, providing no violations of standard English grammar. However, a listener is likely to judge the sentences of (1) as having no relation to one another – as being incoherent as an argument or piece of discourse. The sentences comprising (2) are, however, coherent. Hearing (2) as coherent requires several assumptions. For example, the father’s son and ‘the boy’ are understood as referring to the same person; it must be assumed that what Mom was pleased about was the fact that the boy meant no ill-harm to her flowers; and that the make-believe cutting was done by the toy chainsaw. In the examples stated above, it is notable that discourse coherence depends greatly on semantics. It is the meanings of the sentences that allow the second and last sentences of (2) to follow each other coherently. This is a major obstacle to the application of Kehler’s principles to music, as music has no semantic component to aid coherence. It is clear then that if coherence principles are in operation in music, they would not be operational by virtue of semantics. What then results in us hearing two phrases as part of the same piece of music, or a phrase entailing another phrase? Or, in virtue of what do we judge successive phrases and sections to be parts of the same musical pieces?

In the case of Western tonal music, tonality often serves as a determinant of coherence. For instance, if confronted with a 16-bar section in a piece of Viennese Classical music with a tonality of C major, comprised of an 8-bar forephrase and an 8-bar afterphrase, the piece would be considered less coherent if the afterphrase were transposed to a remote key, such as F sharp major. Similarly, if the afterphrase was completely atonal, it is unlikely that an

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unprepared listener would consider it to be part of the same piece as the forephrase. However, Western music’s fixation with tonality is mostly culturally determined. Many sorts of music do not have a similar emphasis on tonal function and the idea of transposable tonal centres. If we imagine a music that is mono-tonal (that is, remaining in one key), how is coherence further achieved? It may be the case that two successive sections have a common tempo, a common meter, or a similarity in thematic material. Successive sections may have similar pitch contours, or similar rhythmic treatment of material. Timbre and register may be other factors, as can less precise similarities, such as similarity in articulation. These factors lend a degree of coherence to successive sections. The judgement of coherence will be based on a (possibly weighted) judgement of the degree of similarity of successive sections in comparison with differences. Judgements of coherence in musical structures larger than a phrase are likely to place much reliance on statistical processes. For example, successive sections may have a common meter, but different timbres, rhythmic treatment, contour, and tempo, resulting in a lack of coherence between these sections. Coherence rules are unlikely to be hard and fast. Instead they will have to entertain a measure of flexibility, possibly being similar in nature to the preference rules described in the GTTM.

If coherence rules exist and can be described as such, it is likely that a large proportion of them will be stylistically (and hence culturally) determined. For example, sections with different tempos that are unrelated thematically are perceived as separate sections, and were it not for their conventional placement alongside one another, would not be thought of as belonging to the same piece of music. In a similar manner, we are able to distinguish between the movements of a symphony; and despite the fact that the movements of early Classical symphonies are related tonally, we judge them to be separate pieces of music on the basis of tempo and thematic content. Some factors contributing to coherence, like tempo and meter, register, melodic contour, timbre, rhythmic identity, and possibly tonality in some weak sense, may not be culture-specific. I feel that there is an argument to be made for the idea that some basic features of coherence are the product of perceptive discrimination. While the task may appear daunting, it is easily imaginable that matters of coherence are empirically testable in discrimination tests. Thus, researchers may be able to determine what factors lead to a decrease in coherence between successive sections by asking test subjects to discriminate between sections on basis of perceived coherence (e.g. as to whether adjacent sections are considered part of the same or different musical pieces).

Whether coherence rules that are not culturally-derived are the result of general principles of cognition or of the physical constraints of the matter of the mind is an open question. However, it should be noted that in general, as we move from phrases to larger structures, the amount of mental, biologically determined rules progressively diminishes, and the importance of conventional, culturally determined factors increases.120