- Intégrations, op 49 nos 1, 2 (1967)2 pianos
- Intendami chi pó (Ricerca in rime politiche) (2004), 9:004 vocal soloists
- Interactions (1977)string quartet
- Intérieur (2001)incidental music
- Interior at Petworth (2005), 16:00flute, clarinet, piano, percussion, violin, viola and cello
- Interlineal (2017), 10:468-channel fixed medium
- Interlude and Dance (La vida breve) (1904-05)orchestra
- Intermezzo (1973)string orchestra
- horn and piano
- Interplay (1967)flute in
G and piccolo, clarinet, saxophone, percussion and double bass - Interplay (1972)string quartet and accordion
- Interplay (1992), 10:00piano and percussion (vibraphone et marimba)
- Interrupteur (1967)clarinet, bass clarinet, horn, English horn, trumpet, 2 percussions, violin, viola and cello
- iNTERtECTURE (2003), 14:008 musicians
- Intervalles — Intérieurs (1974-82)clarinet, trombone, percussion, violin, cello and fixed medium
- Introspection (1968)3 trumpets, organ and 2 percussions
- Inventions I et II (1961)flute, harp, piano and vibraphone
- The Invisible Singer (2017)theremin, string quartet and processing
- Io amai sempre, 10:00
- Ionisation (1931)13 percussions
- Ire (1992)flute (bass flute), bassoon, alto saxophone, 2 horns, English horn, piano, 2 percussions, 3 cellos and 2 double basses
- Irons (2009-10), 13:00saxophones, contrabassoon, percussion and strings
- Ishuma (1973), 15:00voice, trombone, synthetizer, ondes Martenot, Hammond organ, 3 percussions and violin
- Iskra (2004), 9:24saxophone quartet
- Itinerant: In Memory of Isamu Noguchi (1989), 7:00flute
- violin
