da capo An indication to return to the beginning of a piece.

da capo aria Lyric song in ternary, or A-B-A, form, commonly found in operas, cantatas, and oratorios.

decrescendo The dynamic effect of gradually growing softer, indicated in the musical score by the marking ">." Also referred to as diminuendo.

development Structural reshaping of thematic material. Second section of sonata-allegro form; it moves through a series of foreign keys while themes from the exposition are manipulated.

dialogue opera See ballad opera.

diatonic Melody or harmony built from the seven tones of a major or minor scale. A diatonic scale encompasses patterns of seven whole tones and semitones.

Dies irae Chant from the Requiem Mass whose text concerns Judgment Day.

diminuendo Growing softer.

diminution Statement of a melody in shorter note values, often twice as fast as the original.

disco Commercial dance music popular in the 1970s, characterized by strong percussion in a quadruple meter.

disjunct Disjointed or disconnected melody with many leaps.

dissonance Combination of tones that sounds discordant and unstable, in need of resolution.

divertimento Classical instrumental genre for chamber ensemble or soloist, often performed as light entertainment. Related to serenade and cassation.

Divine Offices Cycle of daily services of the Roman Catholic Church, distinct from the Mass.

doctrine of the affections Baroque doctrine of the union of text and music.

dodecaphonic Greek for "twelve-tone"; see twelve-tone music.

dolce Sweetly.

dolente Sad, weeping.

dominant The fifth scale step, sol.

dominant chord Chord built on the fifth scale step, the V chord.

double bass Largest and lowest-pitched member of the bowed string family. Also called contrabass or bass viol. Photo Icon

double bassoon See contrabassoon.

double exposition In the concerto, twofold statement of the themes, once by the orchestra and once by the soloist.

double-stop Playing two notes simultaneously on a string instrument.

doubles Variations of a dance in a French keyboard suite.

down beat First beat of the measure, the strongest in any meter.

drone Sustained sounding of one or several tones for harmonic support, a common feature of some folk musics.

dulcimer Early folk instrument that resembles the psaltery; its strings are struck with hammers instead of being plucked.

duple meter Basic metrical pattern of two beats to a measure.

duplum Second voice of a polyphonic work, especially the medieval motet.

duration Length of time something lasts; e.g., the vibration of a musical sound.

dynamics Element of musical expression relating to the degree of loudness or softness, or volume, of a sound.