Ambient music has strong roots in pre-electronic music times with early influences from Modernist and Minimalists classical composers. It started to take shape as a genre in the late 1970's but really accelerated in the mid to late 1980's with the emergence of synthesized and electronic music. Throughout the 1990's and 2000's ambient split evolved into and heavily influenced distinct genres such as Chill Out and Trip Hop.
Nowadays there are broadly three groups of Ambient derived music: Ambient, Downtempo and Chill Out, though there are also other discreet off-shoots and of course significant overlap between the main three genre groups.
The style and appeal ranges from the accessible and melodic sounds of Chill Out through to experimental and leftfield Dark Ambient. With the exceptions of New Age and Chill Out music, most of the genres and sub genres are strongly associated with various Electronic Dance Music scenes.