modulation

noun13

1. •
   Modification or regulation of something to achieve an appropriate measure or proportion; (countable) an instance of this.

   • There was a touching modulation in these words about her father that Walter understood too well. — 1846
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. •
   Variation of the intensity, pitch, and tone of the sound of a musical instrument or voice; inflection; (countable) an instance of this.

   • The Rings of the VVind-pipe, are fitted for the Modulation of the Voice. — 1701
5. •
   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.
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. •
   Changing of a thing from one form to another; (countable) an instance of this.
8. •
   The quality of a typeface of having contrasting, thick and thin parts of the strokes; stroke-width variation.

   • Garamond has much modulation, while Helvetica has very little.
9. •
   (no longer used, rare) 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”).
10. •
    (no longer used) 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.
11. •
    (no longer used) Making music or singing; (countable) a melody, a tune; also (chiefly in the plural), a musical note.

    • Join'd to These [birds], / Thousands beside, thick as the covering Leaves / VVhich speck them o'er, their Modulations mix / Mellifluous. — 1728
12. •
    (no longer used) Harmonious use of language in poetry or prose.
13. •
    (no longer used) Any of the musical notes in ecclesiastical modes of music on which a melodic phrase had to begin and end.