Ambient music is a genre of music that emphasizes tone and atmosphere over traditional musical structure or rhythm. A form of instrumental music, it may lack net composition, structured melody, it uses textural layers of sound which can reward both passive and active listening and encourage a sense of calm or contemplation. The genre is said to evoke an "unobtrusive" quality. Nature soundscapes may be included, the sounds of acoustic instruments such as the piano and flute may be emulated through a synthesizer; the genre originated in the 1960s and 1970s, when new musical instruments were being introduced to a wider market, such as the synthesizer. It was presaged by Erik Satie's furniture music and styles such as Jamaican dub music and German electronic music, but was prominently named and popularized by British musician Brian Eno in 1978 with his album Ambient 1: Music for Airports, it saw a revival towards the late 1980s with the prominence of house and techno music, growing a cult following by the 1990s.

Ambient music may have elements of new-age music and drone music, as some works may use sustained or repeated notes. Ambient music did not achieve large commercial success, being criticized as having a "boring" and "over-intellectual" sound, it has attained a certain degree of acclaim throughout the years in the Internet age. Due to its open style, ambient music takes influences from many other genres, ranging from classical, avant-garde music, folk and world music, amongst others; as an early 20th-century French composer, Erik Satie used such Dadaist-inspired explorations to create an early form of ambient/background music that he labeled "furniture music". This he described as being the sort of music that could be played during a dinner to create a background atmosphere for that activity, rather than serving as the focus of attention. In his own words, Satie sought to create "a music...which will be part of the noises of the environment, will take them into consideration. I think of it as melodious, softening the noises of the knives and forks at dinner, not dominating them, not imposing itself.

It would fill up those heavy silences. It would spare them the trouble of paying attention to their own banal remarks, and at the same time it would neutralize the street noises which so indiscreetly enter into the play of conversation. To make such music would be to respond to a need." In the 1960s, many music groups experimented with unusual methods, with some of them creating what would be called ambient music. In 1969, the group Coum Transmissions were performing sonic experiments in British art schools. Many pieces of ambient music were released in England and the United States of America between the late 1960s and the 1990s; some 1960s music with ambient elements include Music for Zen Meditation by Tony Scott, Soothing Sounds for Baby by Raymond Scott, Music for Yoga Meditation and Other Joys by Tony Scott. Developing in the 1970s, ambient stemmed from the experimental and synthesizer-oriented styles of the period. Brian Eno played a key role in its popularization. However, Jamaican dub musicians such as King Tubby, Japanese electronic music composers such as Isao Tomita, as well as the psychoacoustic soundscapes of Irv Teibel's Environments series, German bands such as Popol Vuh, Ash Ra Tempel and Tangerine Dream, predate Eno in the creation of ambient music and/or were contemporaneous with him.

The concept of background or furniture music had existed some time before, but only in the 70s was ambient music first created, which incorporated New Age ideals with the newly invented modular synthesizer. Eno went on to record 1975's Discreet Music with this in mind, suggesting that it be listened to at "comparatively low levels to the extent that it falls below the threshold of audibility", referring to Satie's quote about his musique d'ameublement; the impact the rise of the synthesizer in modern music had on ambient as a genre cannot be overstated. The only limit is with the composer"; the Yellow Magic Orchestra developed a distinct style of ambient electronic music that would be developed into ambient house music. The English producer Brian Eno is credited with coining the term "ambient music" in the mid-1970s, he said that "I just gave it a name. Which is what it needed... By naming something you create a difference. You say. Names are important." He used the term to describe music, different from forms of canned music like Muzak.

In the liner notes for his 1978 album Ambient 1: Music for Airports, Eno wrote: Whereas the extant canned music companies proceed from the basis of regularizing environments by blanketing their acoustic and atmospheric idiosyncrasies, Ambient Music is intended to enhance these. Whereas conventional background music is produced by stripping away all sense of doubt and uncertainty from the music, Ambient Music retains these qualities, and whereas their intention is to "brighten" the environment by adding stimulus to it Ambient Music is intended to induce calm and a space to think. Ambient Music must be able to accommodate many levels of listening attention without enforcing one in particular.

Jason Gerken is an American musician, who has played in Molly McGuire, Open Hand, Project 86, most HUM as well as The Birth Defects and Sie Lieben Maschinen. Gerken took over for Bryan St. Pere of HUM. According to Bruce Fitzhugh, Gerken met the band, Project 86, on a tour of theirs along with Living Sacrifice and Stavesacre. Molly McGuireLime – Hit It! Recordings/Epic Sisters Of – Hit It! Recordings III Season to RiskIn a Perfect World 1992–1997 GunfighterPro-Electric High Noon ShinerStarless The Egg In for the Kill... Kingdom Sessions: Volume One" Project 86Rival Factions The Kane Mutiny EP This Time of Year EP Picket Fence Cartel Kingdom of SnakesKingdom of Snakes The Birth DefectsFirst 8 Mistakes Good WalkersRalkin' Out

The Mark–Houwink equation known as the Mark–Houwink–Sakurada equation or the Kuhn–Mark–Houwink–Sakurada equation or the Landau–Kuhn–Mark–Houwink–Sakurada equation gives a relation between intrinsic viscosity and molecular weight M: = K M a From this equation the molecular weight of a polymer can be determined from data on the intrinsic viscosity and vice versa. The values of the Mark–Houwink parameters, a and K, depend on the particular polymer-solvent system. For solvents, a value of a = 0.5 is indicative of a theta solvent. A value of a = 0.8 is typical for good solvents. For most flexible polymers, 0.5 ≤ a ≤ 0.8. For semi-flexible polymers, a ≥ 0.8. For polymers with an absolute rigid rod, such as Tobacco mosaic virus, a = 2.0. It is named after Herman F. Roelof Houwink. In size-exclusion chromatography, such as gel permeation chromatography, the intrinsic viscosity of a polymer is directly related to the elution volume of the polymer. Therefore, by running several monodisperse samples of polymer in a gel permeation chromatograph, the values of K and a can be determined graphically using a line of best fit.

The molecular weight and intrinsic viscosity relationship is defined. The molecular weights of two different polymers in a particular solvent can be related using the Mark–Houwink equation when the polymer-solvent systems have the same intrinsic viscosity: K 1 M 1 1 + a 1 = K 2 M 2 1 + a 2 Knowing the Mark–Houwink parameters and the molecular weight of one of the polymers allows one to find the molecular weight of the other polymer using a GPC; the GPC sorts the polymer chains by volume and as intrinsic viscosity is related to the volume of the polymer chain, the GPC data is the same for the two different polymers. For example, if the GPC calibration curve is known for polystyrene in toluene, polyethylene in toluene can be run in a GPC and the molecular weight of polyethylene can be found according to the polystyrene calibration curve via the above equation