Chamber music for unusual combination of acoustic instruments was popular among composers interested in exploring timbres and counterpoint. Most of this generation of composers were active in different styles of avantgarde music: concrete, minimalism, electroacoustic, etc. When they approached chamber music, they did so with a mindset that was influenced by the harmonic freedom they had been used to. Their interest for chamber music (music scored for small sets of instruments) was in sharp contrast with the past preeminence of symphonic music: this generation was clearly more interested in subtleties than in grand emotions.

Astor Piazzolla (Argentina, 1921) mixed tango with classical music to compose works for bandoneon and orchestra, such as Buenos Aires (1951) for symphonic orchestra and two bandoneons, the Concerto For Bandoneon (1979) and the suite La Camorra (1988), a tango opera, Maria de Buenos Aires (1967), the Suite for Vibraphone and New Tango Quintet (1986) with jazz vibraphonist Gary Burton, etc.

Toru Takemitsu (Japan, 1930) wed the western aesthetics of impressionism and expressionism with the eastern aesthetic of meditation and contemplation. The resulting synthesis was an elegant exploration of musical chromatism, with little or no interest for dynamics: Requiem for Strings (1959), Eclipse (1966) for biwa and shakuhachi, November Steps (1967) for biwa, shakuhachi and orchestra, Cassiopeia (1971) for orchestra and percussionist, Autumn (1973) for biwa, shakuhachi and orchestra, A Flock Descends Into The Pentagonal Garden (1977) for orchestra, To The Edge Of Dream (1983) for guitar and orchestra, Nostalgia (1987) for violin and orchestra, Tree-line (1988) for chamber orchestra, From Me Flows What You Call Time (1990) for percussion quintet and orchestra.

Daniel Goode (USA, 1936), composed works for solo clarinet, such as Circular Thoughts (1973), and for gamelan ensemble such as Eine Kleine Gamelan Music (1980).

Malcolm Goldstein (USA, 1936) bridged generations and techniques with The Seasons - Vermont (1983), a collage for natural sounds and improvising dissonant ensemble.

Enfant prodige Charles Wuorinen (USA, 1938) was the traditionalist among the pioneers of the Columbia-Princeton Electronic Music Center. He was still very young when he composed works that were traditional in concept but very unusual in practice such as the Concertone for brass quintet and orchestra (1960), the Symphonia Sacra for small orchestra (1961), the Chamber Concerto for cello and small orchestra (1963), that borrowed bits and pieces from Stravinsky's stormy style, Varese's harmonic anarchy and Schonberg's claustrophobic atmospheres, mediated via American revolutionaries such as Elliott Carter and Milton Babbitt. Wuorinen refined his art by trying his hand at just every possible genre, from the electronic poem Time's Encomium (1969), in the vein of Morton Subotnick, to the opera Whore of Babylon (1975) to the Symphony of Percussions (1976). His synthesis reached the zenith with the most ambitious works of his career, notably the Piano Concerto 3 (1983) and the Piano Concerto 4 (2005), the melodramatic and manically intense String Sextet (1989), and the "Dante Trilogy" for chamber orchestra and percussion that comprises The Mission Of Virgil (1993), The Great Procession (1995) and The River of Light (1996).

In the era of the soundscape, composers such as Edgard Varese, John Cage, Harry Partch and Steve Reich turned to percussion ensembles the way that romantic composers used to turn to the symphony orchestra.

Canadian percussion ensemble Nexus pioneered a new genre for western music: ensemble percussion music, with Music of Nexus (1978), although their improvised sound collages, such as, Origins (1992) extended well beyond the usual definition of "percussion".

Another Canadian outfit, the Glass Orchestra, was a quintet of musicians that improvised with a number of instruments made of glass. The Glass Orchestra (1977) focused on a cascade of long hypnotic drones, reminiscent of Indian and Tibetan vocal music.

Daniel Schell (Belgium, 1944) composed the Ishango Oratorio (2003) for guitar, saxophone, bass, choir and African percussion, that mixed jazz, classical and ethnic music,

David Rosenbloom (USA, 1949), whose work straddles the border between classical and popular music, composed the metaphysical suite Departure (1981) for eight voices, three flutes, two oboes, two violins, cello, two doublebasses, soprano sax, French horn, organ, percussion.

Paul Dresher (post-chamber) (USA, 1951) applied the lessons (but not the praxis) of minimalism and of live electronic music to the string quartet Casa Vecchia (1982), the chamber septet Channels Passing (1982) and to Re:act:ion (1984) for symphony orchestra.

Wendy Mae Chambers (post-chamber) (USA, 1953) devoted herself to large-scale neoclassical compositions such as Symphony Of The Universe (1989) for 100 timpani, metal percussion, horn soloist, jazz band, choir, organ, and tape, and A Mass for Mass Trombones (1993), a nine-movement requiem for 77 trombones.

Bun-Ching Lam (China, 1954) incorporated Chinese instruments such as the pipa (four-stringed lute) into the format of Western chamber music. as in Omi Hakkei (2000) for harp, flute, viola (the classic Debussy trio) plus dizi, erhu, xiao and zheng, Song of the Pipa (2001) for pipa, harp, percussion and strings, and Atlas (2004) for Chinese, Middle East and Western instruments. However, the percussion sonata Lu (1983) and the sonata Like Water (1995) for viola, piano and percussion were rarefied pieces that sculpted naked soundscape visited by sporadic tones, but mostly silent.

Jin Hi Kim (Korea, 1957), also a jazz improviser, mixed Korean traditional music (mostly for the komungo zither) and Western chamber music in compositions inspired to the idea that "each tone is alive", such as Nong Rock (1992) for string quartet and komungo.

The chamber music of Allison Cameron (Canada, 1963) emphasized the colors while maintaining a delicate balance of tones and rhythms. A sense of macabre and claustrophobic surfaces from scores such as A Blank Sheet Of Metal (1987) and Gibbons Moon (1991).

Nikola Kodjabashia (Macedonia, 1970) incorporated folk, expressionist and minimalist elements in Bildbeschreibung (2001).

Even veterans of event music returned to the classical formats of large-scale orchestral music, for example: Roger Reynolds' Whispers Out of Time (1988), Frederic Rzewski's The Triumph of Death (1988), Alvin Curran's trio Schtyx (1991) for violin, piano and percussion. Gavin Bryars' Cadman Requiem (1989) and Cello Concerto "Farewell to Philosophy" (1994), James Tenney' In a Large Open Space (1994) and In a Large Reverberant Space (1995) for variable orchestra; etc.

Alaska resident John Luther Adams (1953) composed static music in the minimalist tradition but scored for chamber orchestras. Thus his colossal In The White Silence (1998), The Light That Fills the World (2000) and The Immeasurable Space of Tones (2001) for violin, vibraphone, piano, keyboard and contrabass.

The minimalist tradition was revived in the new century by Dan Joseph (USA, 1966), whose music absorbed influences from folk music from around the world. The exuberant, propulsive, Michael Nyman-esque Percussion and Strings (2004) was performed by a neo-baroque ensemble of violin, cello, harpsichord, hammered dulcimer, clarinet and percussion; whereas Tonalization (2009) was a requiem scored for flute, violin, cello, marimba, harpsichord and hammer dulcimer.

Jazz trumpeter Nate Wooley (USA, 1974) reinvented droning minimalism from the perspective of the free improviser and digital composer with The Almond (2011), a 70-minute "solo" of overdubbed pure-pitched trumpet.

Electroacoustic music

There was live electronic music. There was improvised music. There was computer interactive music. But there were also composers who merely incorporated electronic instruments into the orchestra and remained relatively faithful to the traditional composer/performer paradigm. Electroacoustic music was only apparently revolutionary. What was revolutionary was the virtually infinite repertory of timbres that the electronic instrument could produce, and thus the possibilities for counterpoint and harmony. But the fundamental approach to composing and performing was much closer to the western rational approach of previous centuries than the composers wanted to admit.

trevor wishart's "journey into space" & "red bird", desmond leslie's "music of the future", and basil kirchin's "worlds within worlds" Pentes (1974), the Denis Smalley (New Zealand, 1946)

Trombone player James Fulkerson (USA, 1945) created oneiric soundscapes for his trombone playing, such as Stationary Fields Moving Fields (1979) for amplified trombone, amplified cello and tape delay, and Force Fields and Spaces (1981) for trombone and electronics.

Ekkehard Ehlers (Germany, 1974), an electronic producer operating at the crossroad of post-classical chamber music and digital soundsculpting, was perhaps the first conscious purveyor of digital chamber music on albums such as Politik Braucht Keinen Feind (2003).

Eric Glick-Rieman (USA, 1962) composed Trilogy From The Outside (2008) for prepared piano, acoustic piano, toy piano, celeste, melodica, a self-made bowed instrument and found objects.

Improvised electroacoustic music

The influence of the jazz and rock avantgarde led to a laptop-mediated marriage of electroacoustic music and free improvisation (basically a continuation of live electronic music of the 1960s and 1970s).