Process music in the context of Eighth note

Minimal music (also called minimalism) is a form of art music or other compositional practice that employs limited or minimal musical materials. Prominent features of minimalist music include repetitive patterns or pulses, steady drones, consonant harmony, and reiteration of musical phrases or smaller units. It may include features such as phase shifting, resulting in what is termed phase music, or process techniques that follow strict rules, usually described as process music. The approach is marked by a non-narrative, non-teleological, and non-representational approach, and calls attention to the activity of listening by focusing on the internal processes of the music.

The approach originated on the West Coast of the United States in the late 1950s and early 1960s, particularly around the Bay Area, where La Monte Young, Terry Riley and Steve Reich were studying and living at the time. After the three composers moved to the East Coast, their music became associated with the New York Downtown music scene of the mid-1960s, where it was initially viewed as a form of experimental music called the New York Hypnotic School. In the Western art music tradition, the American composers Moondog, La Monte Young, Terry Riley, Steve Reich and Philip Glass are credited with being among the first to develop compositional techniques that exploit a minimal approach. The movement originally involved dozens of composers, although only five (Young, Riley, Reich, Glass, and later John Adams) emerged to become publicly associated with American minimal music; other lesser known pioneers included Dennis Johnson, Terry Jennings, Richard Maxfield, Pauline Oliveros, Phill Niblock, and James Tenney. In Europe, the music of Louis Andriessen, Karel Goeyvaerts, Michael Nyman, Howard Skempton, Éliane Radigue, Gavin Bryars, Steve Martland, Peter Michael Hamel, Henryk Górecki, Arvo Pärt and John Tavener exhibits minimalist traits.

Stephen Michael Reich (/raɪʃ/ RYSHE; born October 3, 1936) is an American composer best known as a pioneer of minimal music in the mid to late 1960s. Reich's work is marked by its use of repetitive figures, slow harmonic rhythm, and canons. Reich describes this concept in his essay "Music as a Gradual Process" by stating, "I am interested in perceptible processes. I want to be able to hear the process happening throughout the sounding music." For example, his early works experiment with phase shifting, in which one or more repeated phrases plays slower or faster than the others, causing it to go "out of phase." This creates new musical patterns in a perceptible flow.

His innovations include using tape loops to create phasing patterns, as on the early compositions It's Gonna Rain (1965) and Come Out (1966), and the use of simple, audible processes, as on Pendulum Music (1968) and Four Organs (1970). Works like Drumming (1971) and Music for 18 Musicians (1976), both considered landmarks of minimalism and important influences on experimental music, rock, and contemporary electronic music, would help entrench minimalism as a movement. Reich's work took on a darker character in the 1980s with the introduction of historical themes as well as themes from his Jewish heritage, notably Different Trains (1988).

James Tenney (August 10, 1934 – August 24, 2006) was an American composer, music theorist, and pianist. He made significant early musical contributions to plunderphonics, sound synthesis, algorithmic composition, process music, spectral music, and microtonal tuning systems including extended just intonation. His theoretical writings variously concern musical form, texture, timbre, consonance and dissonance, and harmonic perception.

Phase music is a form of music that uses phasing as a primary compositional process. It is an approach to musical composition that is often associated with minimal music, as it shares similar characteristics, but some commentators prefer to treat phase music as a separate category. Phasing is a compositional technique in which the same part (a repetitive phrase) is played on two musical instruments, in steady but not identical tempo. Thus, the two instruments gradually shift out of unison, creating first a slight echo as one instrument plays a little behind the other, then a doubling effect with each note heard twice, then a complex ringing effect, and eventually coming back through doubling and echo into unison.

Phasing is the rhythmic equivalent of cycling through the phase of two waveforms as in phasing. The tempi of the two instruments are almost identical, so that both parts are perceived as being in the same tempo: the changes only separate the parts gradually. In some cases, especially live performance where gradual separation is extremely difficult, phasing is accomplished by periodically inserting an extra note (or temporarily removing one) into the phrase of one of the two players playing the same repeated phrase, thus shifting the phase by a single beat at a time, rather than gradually.

It's Gonna Rain is a tape composition written by American composer Steve Reich in 1965. It lasts about 18 minutes. It was Reich's first major work and is considered a landmark in minimalism and process music.

Pendulum Music (For Microphones, Amplifiers Speakers and Performers) is the name of a work by Steve Reich, involving suspended microphones and speakers, creating phasing feedback tones. The piece was composed in August 1968 and revised in May 1973, and is an example of process music.