Il | A general term that means ‘the.’ (Also la.)
Imitation | The repetition of a phrase or melody in another part or voice (usually at a different pitch) while the first voice continues with new material; a kind of musical ‘follow the leader.’
Impetuoso | (See con passione.)
Impressionism | A musical style of the late nineteenth century that emphasizes mood and atmosphere, rich timbres, elegance, and beauty of sound.
Improvisation | The spontaneous, on-the-spot creation of music while it is being performed. (See also embellisment.)
Incalzando | (See accelerando.)
Incidental music | Music used in a film or play as a background to intensify the mood or drama.
Incomplete cadence | A temporary point of rest in a composition, created by ending a phrase on the dominant seventh chord; the cadence does not sound complete because the dominant seventh feels tense.
Indeterminacy | (See aleatory.)
Indie music | A type of popular music characterized by (real or perceived) independence from commercial pop music and mainstream culture; often features a deliberately unpolished or uncommercialized style.
Industrial music | A general term for different styles of electronic and experimental music; typically a type of harsh rock music that uses sounds that resemble those produced by industrial machinery.
Inflection | Any change or modification of a pitch or note. (See also blue note.)
Inspiration | A creative force or influence. Also the process of being mentally stimulated to do something creative.
Instrument | An object or device used for producing musical sounds.
Instrumental | Music performed by instruments without any vocals or lyrics.
Instrumentation | The particular instruments used in a piece of music. Also the way a piece is arranged for instruments.
Interlude | An optional section, often between the choruses in a song, that adds variety to the music.
Interrupted cadence | (See deceptive cadence.)
Intonation | The ability of a performer to maintain accurate pitch.
Introduction | The opening section in a piece of music; sometimes called the “Intro.”
Inversion | A reversed interval between two notes. Also a chord with a note other than the root on the bottom. Also, in atonal music, the upside-down version of a tone row.
Ionian mode | A mode based on the first degree of a diatonic scale; identical to the major scale. (See also major scale.)
Irish harp | A plucked-string instrument with about thirty strings; used to accompany Irish songs and dance music. (Also Celtic harp.)
Irregular meter | (See odd meter.)
Irregular progression | A chord progression that deviates from a common circle progression by using very unusual chord changes. (See also alternate progression.)