- I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly dreaming I am a man (2001), 28:00MIDI piano (Yamaha Disklavier) and chamber orchestra
- Ic mun wax wode (2006), 7:00
- Icare-apprenti (1970)flute, 2 trumpets, ondes Martenot, 6 percussions and violin
- IF (1992)bass flute in
F - Igniting the Dawn (1996)flute, oboe, clarinet, piano, percussion, violin, cello and double bass
- Iikkii (froidure) (1972)flute (piccolo and flute in
G ), oboe, clarinet, bassoon, horn, trumpet, trombone, tuba, guitar, harp, piano (celesta), 2 percussions, violin, viola, cello and double bass - Ikaros agog… Daidalos on edge (2012), 21:00orchestra
- Iks-Repons (2009)
- Il adressa ces mots (1987)4 horns, 4 trumpets, 2 trombones, 2 tubas and 4 percussions
- Il concertino (1971)solo flute, clarinet, harmonium, piano, percussion, violin, cello and double bass
- Il divertimento barocco (1999), 13:00violin, harpsichord and string ensemble
- il suono blu (2005), 12:0010 musicians
- Il tempo di una canzone (2012)violin and piano
- Il Temps-te (2006), 12:00trumpet and processing
- Illumination II (1969), 22:00flute (piccolo, flute in
G ) and ocarina, B-flat clarinet (E -flat clarinet), bass clarinet, bassoon (double bassoon), horn inF , piano, percussion, violin, viola, cello, double bass and fixed medium - Illuminations (1987)8 violins, 3 violas, 2 cellos and double bass
- Illusions (1971)cello
- Ilôts (2018)piano, violin, viola and cello
- 14 musicians
- Ilynx (version de chambre) (1968)clarinet, piano, 2 percussions and double bass
- electric flute, electric piano, 2 percussions and electric double bass
- Imaginario I (1967)harpsichord and 3 percussions
- Imaginary Opera (2004), 15:00flute, oboe, clarinet, bassoon, piano, 2 percussions, violin, viola, cello and double bass
- Imago (2009)flute, clarinet, piano, percussion, violin, viola, cello and fixed medium
- Immobilis in mobili (1977)flute, oboe, clarinet, violin, viola, cello, 2 pianos and vibraphone
- Impasto (2006-08), 45:46fixed medium
- Impasto 46 (2006), 16:29
- Impasto 128 (2008), 19:31
- Impasto finale (2008), 9:38
- organ (pedalboard solo)
- Impromptu 2 (1995), 16:00piano, synthetizer (Roland JV-80, Max/MSP sampler) and stereo fixed medium