Definitions for **"Proportions"**

general category describing the various cut parameters of a gemstone.

The proportions of a diamond are very important, so that the maximum amount of light can be reflected off and out of a stone. Proportion is the relationship between the angles of the facets of the crown and pavilion. For more information, please visit our diamond education page.

proper or equal share

The size relationships of one part to the whole and of one part to another.

Changes in meter notated by ratios or symbols that reduce or increase the relation of the durations of the notes. The system of proportions is incredibly complex, but the practicing musician need only become familiar with a few in order to perform the great majority of music. However, the availability of proportions made Proportional Canons possible, ie the creation of polyphonic music from a single line by applying both time-relation and pitch-relation changes to produce many parts. Apel shows many of these, which range in complexity from a Josquin 2-part canon to Pierre de la Rue's fuga quatuor vocum ex unica in which one part produces four, each at a different pitch (starting together on G, d, g, and d'), and proceeds at a different rate, so that only one voice actually uses the whole part. Ending places are indicated by signum congruentiae. Also, and according to some theorists, most often, proportions were used to make tenor parts, which would be based on a cantus firmis and changed in each repeat with a new time signature.

equations that show two ratios are equivalent

The relative size of a flag, expressed in terms of its width to length ratio, e.g., 1:2.

A visual order between elements based on a consistent and visually pleasing ratio, which can derive from structural efficiency or be consciously applied for effect.