navigate through a hypertext environment; some works accept textual or visual input from outside; sometimes an audience can influence the course of a performance or can even participate in it.

Though some of the earliest examples of interactive art have been dated back to the 1920s, most digital art didn’t make its official entry into the world of art until the late 1990s.[2] Since this debut, countless museums and venues have been increasingly accommodating digital and interactive art into their productions. This budding genre of art is continuing to grow and evolve in a somewhat rapid manner through internet social sub-culture, as well as through large scale urban installations.
source: http://en.wikipedia.org/wiki/Interactive_art

Installations Art
Installation art describes an artistic genre of three-dimensional works that are often site-specific and designed to transform the perception of a space. Generally, the term is applied to interior spaces, whereas exterior interventions are often called Land art; however, the boundaries between these terms overlap.

Installation art can be either temporary or permanent. Installation artworks have been constructed in exhibition spaces such as museums and galleries, as well as public and private spaces. The genre incorporates a broad range of everyday and natural materials, which are often chosen for their "evocative" qualities, as well as new media such as video, sound, performance, immersive virtual reality and the internet. Many installations are site-specific in that they are designed to exist only in the space for which they were created, appealing to qualities evident in a three-dimensional immersive medium.
source: http://en.wikipedia.org/wiki/Installation_art

Interactive installations Art
What is interactive art? Simply defined, interactive art is a type of installation that allows the audience or spectator to interact with the piece in a way that achieves its desired purpose. According to some, interactive art was first produced in the fifth century B.C. when Parrhasius created a painted curtain that Zeuxis tried to unveil. The work took its meaning from the gesture of the attempted unveil, and the piece would not have existed without said interactivity.

Modern works of interactive art are said to first be seen in the 1920s with a famous example of Marcel Duchamp’s piece named Rotary Glass Plates, which required the viewer to turn on the machine and stand at a distance. Interactive art as we know it today started to take shape in the '60s and '70s when artists began to incorporate new technology, such as computers and video, and experiment with live performances and interactions.

As new media has emerged and technology has become more accessible, interactive art has been shaped in recent years to enable audience and machine to interact easily to create the intended dialogue of the artists.

Types of Interactive installations art
The forms and types of interactive art is very broad and vague. Essentially any piece of art where the audience is able to engage and interact with it directly is interactive art. The artwork is created to have its true meaning and intentions divulged when its interacted with.

The typical types of interactive art include interactive dance, music, or drama, new technology or computerized art, installation art, interactive architecture, and interactive film.
source: http://www.artinteractive.org/interactive-art/

Environment

Definition:
Environment literally means surrounding and everything that affect an organism during its lifetime is collectively known as its environment. In another words “Environment is sum total of water, air and land interrelationships among themselves and also with the human being, other living organisms and property”. It includes all the physical and biological surrounding and their interactions. Environmental studies provide an approach towards understanding the environment of our planet and the impact of human life upon the environment. Thus environment is actually global in nature, it is a multidisciplinary subject including physics, geology, geography, history, economics, physiology, biotechnology, remote sensing, geophysics, soil science and hydrology etc.

source: http://www.newagepublishers.com/samplechapter/001773.pdf

The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species. The concept of the natural environment can be distinguished by components:
Complete ecological units that function as natural systems without massive human intervention, including all vegetation, microorganisms, soil, rocks, atmosphere, and natural phenomena that occur within their boundaries.
Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air, water, and climate, as well as energy, radiation, electric charge, and magnetism, not originating from human activity.
source: http://en.wikipedia.org/wiki/Natural_environment

Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through some medium (like air or water), composed of frequencies which are within the range of hearing.

Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustical engineering may be called an acoustic engineer. (Not to be confused with an audio engineer.) The application of acoustics can be seen in almost all aspects of modern society, subdisciplines include: aeroacoustics, audio signal processing, architectural acoustics, bioacoustics, electroacoustics, environmental noise, musical acoustics, noise control, psychoacoustics, speech, ultrasound, underwater acoustics and vibration.]

Physics of sound

Propagation of sound
Sound is a sequence of waves of pressure that propagates through compressible media such as air or water. (Sound can propagate through solids as well, but there are additional modes of propagation). Sound that is perceptible by humans has frequencies from about 20 Hz to 20,000 Hz. In air at standard temperature and pressure, the corresponding wavelengths of sound waves range from 17 m to 17 mm. During propagation, waves can be reflected, refracted, or attenuated by the medium.

The behavior of sound propagation is generally affected by three things:
A relationship between density and pressure. This relationship, affected by temperature, determines the speed of sound within the medium. The propagation is also affected by the motion of the medium itself. For example, sound moving through wind. Independent of the motion of sound through the medium, if the medium is moving, the sound is further transported. The viscosity of the medium also affects the motion of sound waves. It determines the rate at which sound is attenuated. For many media, such as air or water, attenuation due to viscosity is negligible.

When sound is moving through a medium that does not have constant physical properties, it may be refracted (either dispersed or focused).

The mechanical vibrations that can be interpreted as sound are able to travel through all forms of matter: gases, liquids, solids, and plasmas. The matter that supports the sound is called the medium. Sound cannot travel through a vacuum.

Perception of sound

The perception of sound in any organism is limited to a certain range of frequencies. For humans, hearing is normally limited to frequencies between about 20 Hz and 20,000 Hz (20 kHz), although these limits are not definite. The upper limit generally decreases with age. Other species have a different range of hearing. For example, dogs can perceive vibrations higher than 20 kHz, but are deaf to anything below 40 Hz. As a signal perceived by one of the major senses, sound is used by many species for detecting danger, navigation, predation, and communication. Earth's atmosphere, water, and virtually any physical phenomenon, such as fire, rain, wind, surf, or earthquake, produces (and is characterized by) its unique sounds. Many species, such as frogs, birds, marine and terrestrial mammals, have also developed special organs to produce sound. In some species, these produce song and speech. Furthermore, humans have developed culture and technology (such as music, telephone and radio) that allows them to generate, record, transmit, and broadcast sound. The scientific study of human sound perception is known as psychoacoustics.

Equipment for dealing with sound

Equipment for outputing or generating : musical instrument, sound box, hearing phones, sonar systems, sound reproduction, and broadcasting equipment. Many of these use electro-acoustic transducers for input : microphones .
source: http://en.wikipedia.org/wiki/Sound

Music Genre

A music genre is a conventional category that identifies pieces of music as belonging to a shared tradition or set of conventions. It is to be distinguished from musical form and musical style, although in practice these terms are sometimes used interchangeably.

Music can be divided into different genres in several ways. The artistic nature of music means that these classifications are often arbitrary and controversial, and some genres may overlap. There are several academic approaches to genres. In his book Form in Tonal Music, Douglass M. Green lists madrigal, motet, canzona, ricercar, and dance as examples of genres from the Renaissance period. According to Green, "Beethoven's Op. 61 and Mendelssohn's Op. 64 are identical in genre – both are violin concertos – but different in form. However, Mozart's Rondo for Piano, K. 511, and the Agnus Dei from his Mass, K. 317 are quite different in genre but happen to be similar in form." Some, like Peter van der Merwe, treat the terms genre and style as the same, saying that genre should be defined as pieces of music that share a certain style or "basic musical language". Others, such as Allan F. Moore, state that genre and style are two separate terms, and that secondary characteristics such as subject matter can also differentiate between genres. A music genre or sub-genre may be defined by the musical techniques, the styles, the context, and content and spirit of the themes. Geographical origin is sometimes used to identify a music genre, though a single geographical category will often include a wide variety of sub-genres.

Among the criteria often used to classify musical genres are: the trichotomy of art, popular and traditional; time period; regional and national origins; technique and instrumentation; fusional origins; and social function.
source: http://en.wikipedia.org/wiki/Music_genre

The genealogy of musical genres is the pattern of musical genres that have contributed to the development of new genres.

Genealogical charts or family trees of musical genres show how new genres have emerged from existing genres and how multiple genres have contributed to a new genre. Since music can be endlessly broken down into smaller and smaller categories, a genealogical chart will usually focus on one major genre and its different strains. For instance, jazz is considered to be a genre with many sub-genres, including New Orleans jazz, ragtime, swing, bebop, free jazz, and Latin jazz. How these developed out of one another is shown in a genealogical chart, often with major figures or innovators of each sub-genre.

A genealogy of genres may also incorporate several major genres, such as jazz, rock and roll and folk music. The image accompanying this article shows how numerous Cuban musical styles have developed out of many other genres including some from Europe, Africa, the US, Latin America and other Caribbean countries. While focusing on Cuban music, the image also shows the genealogy of many popular music genres since the 18th century.

The family tree of music can also be explored by starting at the article for your favourite genre, and clicking on the items in the stylistic origins, subgenres, derivative forms, and fusion genres sections of the genre infobox.
source: http://en.wikipedia.org/wiki/Genealogy_of_musical_genres

Environment Sound
Natural sounds are sounds produced by natural sources in their normal soundscape. It is a category whose definition is open for discussion, see the section below. The category includes the sounds of any living organism, from insect larvae to the largest living mammal on the planet, whales, and those generated by natural, non-biological sources. In most respects, the natural habitats from which these acoustic sources emanate, are defined as not heavily impacted by human intervention.

The historical background of natural sounds as they have come to be defined, begins with the recording of a single bird, by Ludwig Koch, as early as 1889. Koch's efforts in the late 19th and early 20th centuries set the stage for the universal audio capture model of single-species—primarily birds at the outset—that subsumed all others during the first half of the 20th century and well into the latter half and into the early 21st, as well. In late 1968, influenced by acoustic efforts in the fields of music and film, this model began to evolve into a much more holistic effort with attention paid to the acoustic experience of entire habitats, inclusive of all the wild animal voices. Expressed as wild soundscapes, these phenomena included sounds primarily from two main sources, non-human and non-domestic wild ones, and non-biological sources in relatively undisturbed habitats. In the early years of the 21st century, the definition of the soundscape was broken down into three components: the geophony, non-biological natural sounds that include the effects of water by a stream or waves at the ocean, the effects of wind in the trees or grasses, and sound generated by the earth, itself, for example, glaciers, avalanches and earthquakes; the biophony, all the non-human, non-domestic sounds that emanate from a relatively undisturbed habitat; and anthrophony, all sound generated by human endeavor, whether music, theatre, or electromechanical.

Humans are a product of nature thus could be considered part of nature. Except that humans have long-considered themselves to be separate and in conflict. For that reason, a special category of the soundscape has been set aside for human, alone. Called anthrophony, it includes all of the sound that humans produces, whether structured (i. e. music, theatre, film, etc), or entropic, as in the electromechanical chaotic and uncontrolled signals we generate by whatever means. Anthrophony has a profound effect on the natural soundscape and the featured organisms who play seminal roles in those habitats. But the nature of that effect varies with the types and families of sound and their relative intensity. Natural sounds are restricted to natural sources in their normal soundscape because clips of isolated natural sources are like sound bites: without context the sounds are prone to be misinterpreted.

Humans
Humans can benefit from natural environments to restore from stress and directed attention fatigue. A human can endure high levels of stress for short time periods as long as these periods are interrupted by restoration moments.

While a natural environment provides more sensory input than the soundscape there are indications that the soundscape alone also affords restoration. A majority of humans indicate that they find natural sounds pleasurable.

Animals

Warning sounds
These are sounds made by animals to warn others, of their species, of impending danger. Similar "warning" sounds are made by those of any unique species when a predator is approaching that species' territory, warning others to seek safety.
Territory sounds

These are sounds, calls, or audible signals made by any one species to its own or any other species, establishing boundaries so like or unlike species will not transgress those boundaries.

Male baboons make sounds heard for miles by other baboons, communicating to those other male baboons, the territory of that male baboon. The strength, volume, and timbre, inherent in that "call", determine whether or not rival males attempt to invade that male baboon's territory.

They do this to make them sound impressive and then to attract the female to them.
Courtship and/or mate attracting sounds

These are sounds made by the male baboon to attract females to his territory for courtship and mating. Again, the strength, quality, and timbre of those sounds, often determine the ability of that species to attract females for reproduction. These mating calls, often low and guttural, are the main criteria, used by the female baboon to determine which male she mates with.
source: http://en.wikipedia.org/wiki/Natural_sounds

Ultrasound
animal echolocation
microchiropterans a.k.a. microbats: carnivorous bats (not fruit bats or flying foxes)
cetaceans: dolphins, porpoises, orcas, whales
two bird species: swiftlets and oilbirds
some visually impared humans have learned this technique
sonar (an acronym for sound navigation and ranging) including
bathymetry
echo sounding
fish finders
medical ultrasonography (the images generated are called sonograms).

Typical parameters used for medical ultrasound
Frequency Hearing Ranges for Selected Animals (60 dB)
source: http://physics.info/sound/

Environment Sound relate to Emotional
That music can profoundly effect our moods is a fact of e very-day life. However, the manner in which music helps arouse feelings, ranging from joy and belongingness to bittersweet sadness and despair, remains a great mystery. Presumably, if we did not possess the kinds of social-emotional brains that we do, human music would probably be little more than cognitively interesting sequences of sounds and, at worst, irritating caco-phonies. Instead, it can help create a variety of peak human affective experiences (Gabrielsson,1991). While some argue that music does not reflect evolved processes of our brain (e.g.Pinker(1997) who called music ‘cultural cheesecake’), others have suggested that it is an important ingredient in the overall recipe of our evolutionary fitness (e.g.Miller (2000), who emphasized that it helps facilitate the success of male sexual court-ship). In any event, most of us listen to music for the emotional richness it adds to our lives, and we rapidly become attached to the music that moves us, yielding, we suspect, bonds that may have underlying neurobiological similarities to the love and social devotion that people often feel for each other. As many have declared, music is the language of emotions.
source: http://www.musikament.at/b3/Panksepp%26Bernatzky.pdf

For many, music exists to express emotions. Music stimulates both psychological mood and physiological changes including heart rate and breathing. Music can help anxiety. It drives the body with loud, fast music making people lively and promoting dance. Slow, soft music can make people calm or sad. Are these inherent responses to music or are they culturally learned? To find out we must look at the brain responses to music emotion and evolution.

Mood Music
There are many characteristics of music affecting our emotions. Sad music seems to use lower pitch, smooth transitions, and low intensity movements. Happy music appears to use loud, fast and high pitch, associated with rapid high-energy movements used for dancing. While music effects physiological system, it also stimulates the reward centers. In fact, music can be addictive, bringing great rewards in the excitement of playing live music, dancing at live concerts, and just listening to that favorite song over and over

How is Emotion Expressed?
One way to look at emotion in music is through inherent aspects of the structure of music – major/minor mode, tempo, timbre, melody, etc. Another way is to examine whether expectation and emotion flows from performance.

Emotion is expressed by the subtle changes musicians make in music not the repetition. Technically excellent musicians are not considered interesting without alterations and changes in their renditions. It is the interpretation that is expressive. Music that is mathematically averaged is not interesting. But, if there are too many changes people don’t like that either.

The more surprising the piece is the more emotion is generated. A march in a minor scale that breaks into a major causes goose bumps. Also emotion depends upon imperfections, which can be seen at live concerts.

When studying emotion in music, autistic people could tell if the piece was supposed to be happy, sad or scary, although they personally found them equal.

Roots of Music and Emotion

Experience builds and then prunes neural networks related to experience with sounds for language and music. Mice with an environment of only white noise, with no rhythm or pitch, do not later recognize the sounds of life and have impaired ability to recognize pitch.

Some types of music appear to trigger specific emotions, but it is not clear if it is based on culture or biology:
Loud, low, sounds with dissonant intervals stimulate fear. Lullabies are sung to children in certain tones that are different than normal speech. Lullabies are lower, slower and softer. For children’s play, songs are faster, higher with prominent rhythm. Children become used to these tones and prefer them. 

Falling pitch denotes comfort. Wide ranging pitch, often bell shaped, means joy or surprise. When babies are rocked to sleep with singing, the major rhythm is breath and heart beat. These movements and sounds become neural networks.

When music produces chills down the spine, the effect is from reward brain centers in nucleus accumbens, brainstem, forebrain, and amygdala with cortex orbitofrontal and insula – same as any other reward for food, sex, drugs. Why does an abstract sound stimulate these centers? Usually because of the associations and expectations. It is possible that most of the emotional responses of music are culturally determined and trained.

Some believe that dissonance is inherent in the anatomy of the ear. Dissonant intervals cause specific vibrations in the basilar membrane of the cochlea triggering neuronal firing. The basilar membrane vibrates in several places when a chord is played and these interact. Also, it is difficult to hear chords if there are many different tones in it. The different sounds make wave interference patterns on the membrane itself.