- Siddhartha (1976), 27:00orchestra
- Sieben frühe Lieder (1880-89)Arr. John Rea, 2002voice and chamber orchestra
- Siegfried-Tableaux (1992)flute
- Siegfriedp’ (1972)cello
- Sieidi (2010), 35:00
- Sieves (2004-05), 15:58videomusicvideo
- Le signe du Lion (1981)horn and tam-tam
- Le silence des foules (2022-23), 8:00
- Silence Not Absence (2018)2 musicians, non-visual scores and an audience with cellphone score interfaces
- Silent Scream Quartet (1991)string quartet
- Simple Loops in Complex Times (2014), 15:00electric guitar and “looper”
- Sinfonie pour orchestre, 15:59
- Energish, 4:38
- Sturmish zupackend, 7:07
- Sinfonietta (2004), 25:00orchestra
- Singulari-T (Tombeau de Ligeti) (2007), 16:00chamber orchestra (15 musicians)
- Sirènes (1999), 10:006 a capella female voices
- gamelan
- Six Bagatelles (1953), 13:00wind quintet
- Six Bagatelles, op 9 (1913), 4:00string quartet
- Six chansons, 7:00
- 2 pianos
- Six-Footer-Music (2021), 30:0025 or more wind instruments (at will) with audio scores
- Six Ings (1916)piano
- keyboard and violin
- Six thèmes solaires (1990), 50:00
- piano
- alto saxophone
- soprano (or tenor or baritone) and piano
- clarinet and piano
- trumpet and piano
- horn and piano
- flute
- violin
- viola and piano
- cello
- Six voices for sirens (2000), 15:004 sopranos and 2 mezzo-sopranos
- Six Waves (2013)flute, clarinet, violin, cello, piano and fixed medium
- 6 violins, 2 violas, 2 cellos and double bass
- Skelter (1997)saxophone quartet (two alto saxophones, and two baritone saxophones)
