IDIOPHONE - A musical instrument that creates sound through its own vibration. Most percussion instruments, with the exception of drum, are idiophones.
IMPRESSIONIST ERA - (1890-1920) Lead by the French, the musical movement was founded as a reaction to the excesses of the Romantic Era. Famous composers of the Impressionistic Era include Claude Debussy and Maurice Ravel.
IMPROVISATION - The act of creating music spontaneously.
INCIDENTAL MUSIC - Background music for a movie, television show or play that is used to set the mood and enhance the action.
INSTRUMENT - Any object that produces a musical sound.
INSTRUMENTATION - The instruments called for in a musical score.
INTERVAL - The distance between two notes.
INTERLUDE - Music played between two larger sections of music, or music played between the acts of an opera or play.
INTERMEZZO - Interlude.
INVERSION (CHORDS) - A chord changed from root position to an arrangement where a pitch other than the root serves as the lowest sounding tone. For example: C chord in root position c-e-g; C chord in first inversion e-g-c; C chord in second inversion g-c-e.
IRISH WHISTLE - A simple six-holed woodwind instrument most often played by Celtic music groups. Also called a "Tin Whistle" or "Penny Whistle".