A style of music and improvisation that combines avant-garde art music and composition with jazz. Avant-jazz often sounds very similar to free jazz, but differs in that, despite its distinct departure from traditional harmony, it has a predetermined structure over which improvisation may take place. This structure may be composed note for note in advance, partially or even completely.

Source: http://en.wikipedia.org/wiki/Avant-garde_jazz

A subgenre of heavy metal music loosely defined by use of experimentation and characterized by the use of innovative, avant-garde elements, large-scale experimentation, and the use of non-standard and unconventional sounds, instruments, song structures, playing styles, and vocal techniques. It evolved out of progressive rock, jazz fusion, and extreme metal, particularly death metal and black metal. Experimental metal also uses unusual sounds, breaks conventions, and often includes new elements. The lyrics and visual presentation of the genre are eclectic as well.

Source: http://en.wikipedia.org/wiki/Experimental_metal

A type of music based on rock which experiments with the basic elements of the genre, or which pushes the boundaries of common composition and performance technique. Performers may also attempt to individualize their music with unconventional time signatures, instrumental tunings, unusual harmony and key signatures, compositional styles, lyrical techniques, elements of other musical genres, singing styles, instrumental effects or custom-made experimental musical instruments.

Source: http://en.wikipedia.org/wiki/Experimental_rock

A form of music that is made in part from acousmatic sound in addition to sounds derived from musical instruments or voices. It is the incorporation of electric sound production into compositional practice. It may use other sources of sound such as electronic synthesizers or sounds recorded from nature. Also, the structure of the compositions is not restricted to the normal musical rules of melody, harmony, rhythm, metre and so on.

Other Terms & Sub-Genres: Tape Music, elektronische Musik, Circuit Bending, Acousmatic Music, Computer Music, Digital Signal Processing, Electronic Art Music, Electroacoustic Improvisation, Japanoise, Prepared Instruments, Sonology, Sound Recording & Reproduction, Sound Sculpture

Source 1: http://en.wikipedia.org/wiki/Electroacoustic_music

Source 2: http://en.wikipedia.org/wiki/Musique_concrète

An international network of artists, composers and designers noted for blending different artistic media and disciplines. The Fluxus movement... developed its 'anti-art', anti-commercial aesthetics under the leadership of George Maciunas. The movement, which still continues, played an important role in the opening up of definitions of what art can be. The origins of Fluxus lie in many of the concepts explored by composer John Cage in his experimental music of the 1950s. Fluxus encouraged a “do-it-yourself” aesthetic, and valued simplicity over complexity. Like Dada before it, Fluxus included a strong current of anti-commercialism and an anti-art sensibility, disparaging the conventional market-driven art world in favor of an artist-centered creative practice.

Source: http://en.wikipedia.org/wiki/Fluxus

improvised music without any rules beyond the logic or inclination of the musician(s) involved. The term can refer to both a technique (employed by any musician in any genre) and as a recognizable genre in its own right. Conventional songs are highly uncommon in free improvisation; more emphasis is generally placed on mood, texture or more simply, on performative gesture than on preset forms of melody, harmony or rhythm. These elements are improvised at will, as the music progresses. As it has influenced and been influenced by other areas of exploration, aspects of modern classical music (extended techniques), noise rock (aggressive confrontation and dissonance), IDM (computer manipulation and digital synthesis), minimalism and electroacoustic music can now be heard in free improvisation.

Source: http://en.wikipedia.org/wiki/Free_improvisation

A style of music that draws on transgressive and provocative themes. Allmusic defines industrial as the "most abrasive and aggressive fusion of rock and electronic music"; "initially a blend of avant-garde electronics experiments (tape music, musique concrète, white noise, synthesizers, sequencers, etc.) and punk provocation". The first industrial artists experimented with noise and aesthetically controversial topics, musically and visually, such as fascism, serial killers and the occult. Their production was not limited tThe first industrial artists experimented with noise and aesthetically controversial topics, musically and visually, such as fascism, serial killers and the occult. Their production was not limited to music, but included mail art, performance art, installation pieces and other art forms.

Source: http://en.wikipedia.org/wiki/Industrial_music

Music with a lower quality of sound recordings than the usual standard for music. The qualities of lo-fi are usually achieved by either degrading the quality of the recorded audio, or using certain equipment. Many lo-fi artists use inexpensive cassette tape recorders. The term was adopted by WFMU DJ William Berger who dedicated a half hour segment of his program to home recorded music throughout the late '80s under the name lo-fi.

Other Terms & Sub-Genres: Low Bit, No-Fi, Cassette Culture

Source: http://en.wikipedia.org/wiki/Lo-fi_music

Music using microtones—intervals of less than an equally spaced semitone. Microtonal music can also refer to music which uses intervals not found in the Western system of 12 equal intervals to the octave. The term implies music containing very small intervals but can include any tuning that differs from the western 12-tone equal temperament. Terminology other than "microtonal" is used by theorists and composers. Ivan Wyschnegradsky used the term ultra-chromatic for intervals smaller than the semitone and infra-chromatic for intervals larger than the semitone.

Source: http://en.wikipedia.org/wiki/Microtonal_music

A style of music associated with the work of American composers La Monte Young, Terry Riley, Steve Reich, and Philip Glass. It was initially viewed as a form of experimental music called the New York Hypnotic School. Prominent features of the style include consonant harmony, steady pulse (if not immobile drones), stasis or gradual transformation, and often reiteration of musical phrases or smaller units such as figures, motifs, and cells. It may include features such as additive process and phase shifting which leads to what has been termed phase music. Minimal compositions that rely heavily on process techniques that follow strict rules are usually described using the term process music.
Leonard Meyer described minimal music in 1994: Because there is little sense of goal-directed motion, [minimal] music does not seem to move from one place to another. Within any musical segment there may be some sense of direction, but frequently the segments fail to lead to or imply one another. They simply follow one another.

Other Terms & Sub-Genres: Post-Minimalism, Process Music, Repetitive Music, Drone Music

Source: http://en.wikipedia.org/wiki/Minimalist_music

A category consisting of multiple discrete genres of music that have employed noise as a musical resource. It can feature acoustically or electronically generated noise, and both traditional and unconventional musical instruments. It may incorporate live machine sounds, non-musical vocal techniques, physically manipulated audio media, processed sound recordings, field recordings, computer generated noise, stochastic processes and other randomly produced electronic signals such as distortion, feedback, static, hiss and hum. There may also be emphasis on high volume levels and lengthy, continuous pieces. More generally noise music may contain aspects such as improvisation, extended technique, cacophony and indeterminacy, and in many instances conventional use of melody, harmony, rhythm and pulse is often dispensed with. The Futurist art movement was important for the development of the noise aesthetic, as was the Dada art movement and later the Surrealist and Fluxus art movements. Contemporary noise music is often associated with extreme volume and distortion.

Source: http://en.wikipedia.org/wiki/Noise_music