| Term | Description |
|---|
| Idiophone | An idiophone is any musical instrument which creates sound primarily by way of the instrument vibrating itself, without the use of strings or membranes. |
| Imitation | In music, imitation refers to the repetition of a phrase played on one instrument or voice by another. |
| Impressionist music | Impressionist music is usually based on atmospheric effects or descriptive ideas. Claude Debussy and Maurice Ravel of France wrote music with sounds that call forth such images as moonlight, waterfalls and fireworks. |
| Impromptu | An impromptu (loosely meaning "offhand") is a free-form musical composition with the character of an improvisation, usually for a solo instrument, such as piano. |
| Improvisation | Improvisation is the practice of acting, singing, talking and reacting, of making and creating, in the moment and in response to the stimulus of one's immediate environment. This can result in the invention of new thought patterns, new practices, new structures or symbols, and/or new ways to act. |
| Incidental music | Incidental music is music in a play, television program, radio program, video game,film or some other form not primarily musical. |
| Indian classical music | The origins of Indian classical music can be found from the oldest of scriptures, part of the Hindu tradition, the Vedas. Samaveda, one of the four Vedas, describes music at length. |
| Indigenous music | Indigenous music may refer to any of the musics of indigenous peoples, especially the folk, ceremonial or ritual, and religious traditions of those people. |
| Inharmonicity | In music, inharmonicity is the degree to which the frequencies of overtones (known as partials, partial tones, or harmonics) depart from whole multiples of the fundamental frequency. Many percussion instruments, such as cymbals, tam-tams, and chimes, create complex and inharmonic sounds. |
| Interlude | In music, interlude is a separate creation/movement or a part of a single movement. |
| Intermezzo | In music, an intermezzo (pl. intermezzi), in the most general sense, is a composition which fits between other musical or dramatic entities, such as acts of a play or movements of a larger musical work. |
| Interval | In music theory, the term interval describes the difference in pitch between two notes. Although frequently used in connection with intervals, the term "distance" does not adequately describe the physics and subjective effects of two interacting frequencies. |
| Introduction | In music, the introduction is a passage or section which opens a movement or a separate piece. In popular music this is often called an intro. |
| Introit | The Introit (Latin: introitus, "entrance") is part of the opening of the celebration of the Roman Catholic Mass and the Lutheran Divine Service. Specifically, it refers to the antiphon that is spoken or sung at the beginning of the celebration. |
| Inuit throat singing | Inuit throat singing or katajjaq, also known under the generic term overtone singing, is a form of musical performance among the Inuit. |
| Invention | In music, an invention is a short composition (usually for a keyboard instrument) with two-part counterpoint. |
| Inversion | In music theory, the word inversion has several meanings. There are inverted chords, inverted melodies, inverted intervals, and (in counterpoint) inverted voices. The concept of inversion also plays a role in musical set theory. |
| Ionian mode | The Ionian mode is a musical mode of diatonic scale. It was part of the music theory of ancient Greece, and was based around the relative natural scale in C. |
| Irrational rhythm | In music, the term irrational rhythm is usually applied to a rhythm in which an unusual number of beats is superimposed on the predominating tempo. |
| Italian overture | The Italian overture is a piece of orchestral music with which in the late 17th and early 18th century several operas, oratorios and other large-scale works opened. |
