modulation

noun

1. Modification or regulation of something to achieve an appropriate measure or proportion; (countable) an instance of this.
2. Variation (especially softening or toning down) of brightness, form, etc.; (countable) an instance of this.
3. Variation in the activity or form of a cell in response to changes in the environment; (countable) an instance of this.
4. Chiefly preceded by a descriptive word: modification of an electromagnetic wave or other oscillating carrier wave to apply a signal to it; (countable) an instance of this; also, the extent to which such a wave is modified; and the modified wave or signal.
5. Variation of the intensity, pitch, and tone of the sound of a musical instrument or voice; inflection; (countable) an instance of this.
6. Changing of the key in a piece of music; also, the effect achieved by this as an element of harmony; (countable) an instance of this.
7. The quality of a typeface of having contrasting, thick and thin parts of the strokes; stroke-width variation.
8. Changing of a thing from one form to another; (countable) an instance of this.
9. Harmonious use of language in poetry or prose.
10. Modification of the parts of a classical Greek or Roman building to achieve appropriate proportions by measuring in modules (“standard units of measure, usually the diameter or radius of a column at the base of a shaft”).
11. Any of the musical notes in ecclesiastical modes of music on which a melodic phrase had to begin and end.
12. Arrangement or composition, or performance, of music in a certain key or mode; also (countable) a series of musical notes, chord, or tune analyzed according to a key or mode.
13. Making music or singing; (countable) a melody, a tune; also (chiefly in the plural), a musical note.