Chill out music (sometimes also chillout, chill-out, or simply chill) is an umbrella term for several styles of electronic music characterized by their mellow style and mid-tempo beats — “chill” being derived from a slang injunction to “relax.” Chill out music emerged in the early and mid-1990s in “chill rooms” at dance clubs, where more relaxing music was played to allow dancers a chance to “chill out” from the more emphatic and fast-tempo music played on the main dance floor. The genres associated with chill-out are mostly ambient, trip-hop, nu jazz, ambient house, ambient trance, New Age and other sub-genres of downtempo—a major branch of electronic music. Sometimes the easy listening sub-genre lounge is considered to belong to the chill-out collection as well. Chill out as a musical genre or descriptive is synonymous with the more recently popularized terms “smooth electronica” and “soft techno” and is a loose genre of music blurring into several other very distinct styles of electronic and lo-fi music.
Lounge music is a retrospective description of music popular in the 1950s and 1960s encompassing the exotica, easy listening, and space age pop genres. It is a type of mood music meant to evoke in the listeners the feeling of being in a place — a jungle, an island paradise, outer space, et cetera — other than where they are listening to it.  The range of lounge music encompasses beautiful music-influenced instrumentals, modern electronica (with chillout, nu-jazz and downtempo influences), while remaining thematically focused on its retro-space-age cultural elements. The earliest type lounge music appeared during the 1920s and 1930s, and was known as light music. Contemporaneously, the term lounge music also denotes the types of music played in hotels (the lounge, the bar), casinos, and piano bars.
Ambient music is a musical genre in which sound is more important than notes.It is generally identifiable as being broadly atmospheric and environmental in nature. Ambient music evolved from early 20th century forms of semi-audible music, from the impressionism to Brian Eno’s deliberate sub-audible approach. Later developments found the dreamy non-linear elements of ambient music applied to some forms of rhythmic music presented in chill-out rooms at raves and other dance events, but always with the primary feature that the music is intended to drift in and out of the listener’s awareness while creating its effect on the listener’s consciousness.
Easy listening is a style of popular music and radio format that emerged in the mid-20th century, evolving out of swing and big band music, and related to Beautiful music and Light music. Easy listening music features simple, catchy melodies, soft, laid-back songs and occasionally rhythms suitable for couples dancing. The genre includes both instrumental forms (often played on light of tone instruments such as the Hammond Organ, violin or ukulele); and vocal forms featuring pop singers and some exotica artists. Easy listening is similar to what is called lounge music, but lounge is more jazz-oriented and dependent on musical improvisation than easy listening. Easy listening music is usually orchestrated by an arranger rather than improvised by a small ensemble. Easy listening music is also sometimes referred to as mood music or elevator music (lift music in the UK). The term muzak is occasionally used as a (usually derogatory) synonym for easy listening music as well, but that is erroneous as Muzak specifically refers to the music produced and programmed for public places by the Muzak Corporation, and is not a music genre in itself. The term easy listening is often incorrectly applied to other genres such as soft rock, smooth jazz, ambient music or new age music. This is because the definition is relatively broad.
Psybient, also known as ambient psy, psychedelic ambient, ambient goa, ambient psytrance and more commonly within the Goa/psytrance scene as psychill and psydub, is a genre of electronic music that combines elements of psychedelic trance, ambient, world music, new age and even ethereal wave. It often has many dub influences and can also sound somewhat like glitch. Psybient pieces are often structured around the concept of creating a “sonic voyage” or “musical journey”. Although similar to psytrance’s emphasis on maintaining non-stop rhythm throughout the night, psybient is far more focused on creating a vast soundscape that can be experienced over the length of an album, focusing less on beatmatching and allowing for a myriad of tempo changes. Some of the most popular and genre leading psybient artists include Shpongle, Entheogenic, Shulman, Ott, Third Ear Audio, Doof, Warp Technique, Yestegan chaY, Younger Brother, The Infinity Project, Pitch Black, The Mystery Of The Yeti, Celtic Cross, and Androcell .
Nu jazz is an umbrella term coined in the late 1990s to refer to music that blends jazz elements with other musical styles, such as funk, soul, electronic dance music, and free improvisation. Also written nü-jazz or NuJazz, it is sometimes called electronic jazz, electro-jazz, e-jazz, jazztronica, jazz house, phusion, “neo-jazz” or future jazz. According to critic Tony Brewer, Nu Jazz is to (traditional) Jazz what punk or grunge was to Rock, of course.
[...] The songs are the focus, not the individual prowess of the musicians. Nu Jazz instrumentation ranges from the traditional to the experimental, the melodies are fresh, and the rhythms new and alive. It makes Jazz fun again.
Downbeat (or Downtempo) is a laid-back electronic music style similar to ambient music, but usually with a beat or groove unlike the beatless forms of Ambient music. The beat is sometimes made from loops that have a hypnotic feeling. Sometimes the beats are more complicated and more featured instead of being in the background, but even then they are usually less intense than other kinds of electronic music like Trance. Often the name chill-out music is used to refer to songs demonstrative of the genre, but those names also refer to other styles of music, and downtempo encompasses a wider variety of styles than those terms alone would indicate. Another related genre is trip hop, though downtempo usually uses a slower tempo than trip hop. Due to the relaxing and often sensual or romantic feel of most downtempo music, along with the absence or minimal use of lyrics or vocals, it is a popular form of background music in ‘chill out rooms’ of dance parties, and many alternative cafes.
Trip hop is a music genre consisting of downtempo electronic music. It began in the early-1990s, growing out of England’s hip hop and house scenes, including that of the Bristol underground. It has been described as “Europe’s alternative choice in the second half of the ’90s”, and “a fusion of hip hop and electronica until neither genre is recognisable.”
Deep house is a subgenre of house music that fuses elements of Chicago house into the 1980s jazz-funk and touches of soul music. In the early compositions (1988—89), influences of jazz music were most frequently brought out by using more complex chords than simple triads (7ths, 9ths, 13ths, suspensions, alterations) which are held for many bars and give compositions a slightly dissonant feel. Later deep house tracks (1993—94) were also heavily influenced by disco and even merged into a disputable disco house genre. The use of vocals became more common in deep house than in many other forms of house music. Sonic qualities include soulful vocals, slow and concentrated dissonant melodies, smooth, stylish, and chic demeanor. Deep house music rarely reaches a climax, but lingers on as a comfortable relaxing sound, with or without vocals.
DUBTECHNO / DUBTRONICA
According to a 2003 newspaper article in Miami New Times, Dubtronica is a genre of music that combines electronica and dub. The origin is thought to be either the experimental English dub of On-U Sound Records and Mad Professor in the 1980s, or glitch techno of Germany during the 1990s. Note that the term is not universally accepted by both artists and listeners, with many opting simply to call the music “dub” or “techdub”. Dubtronica consists of electronic beats played in a downbeat manner. It is much lower in speed than techno and generally warmer than dance-oriented electronica. The genre is repetitive but rewards careful listener attention. Some tracks use reggae toasters or singers to produce a more accessible form of the music.