Music has a hierarchical structure, so
that small units, such as melodical gestures, join to form subphrases, which join to form phrases etc. When musicians
play, they mark the endnings of these tone groups.
This rule marks the phrase and subphrase endings by creating minute accelerandos and decelerandos within phrases
and subphrases according to a parabolic function. Thus it increases the tempo in the beginnings and decreases it
towards the endings.
The loudness is changed similarly creating crescendos and diminuendos.
The phrases and subphrases have been marked in the score file.
In this example two other rules are applied:
You can vary the effect of the Phrase Arch rule only.
Example: F Mendelsohn, Aria # 18 from "St. Paul", Op. 36.
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k = 0 |
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k = 1.5 |
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k = 2.5 |
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k = -1.5 |
The graph shows how much the durations of the tones are changed in % of their nominal duration.
No-Phrasing, k = 0 |
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Medium, k = 1.5 |
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Exaggerated, k = 2.5 |
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Inverted, k = -1.5