Brian Eno's original definition of ambient music came from the liner notes to his seminal 1978 ambient album ‘Ambient 1: Music for Airports’. Eno said that ambient music must be as ignorable as it is interesting. He said it must be able to accommodate many levels of listening attention without enforcing one in particular.
This is a wonderful definition by the widely considered father of ambient music, even though the genre can be traced way back before Eno. Certainly a piece of ambient music was written by the French composer Erik Satie in 1888. Satie in fact wrote three influential, short atmospheric pieces, which he called Gymnopedies, or Trois Gymnopedies. Whilst not technically defined as ambient, Satie’s pieces had the undefinable quality of mood and atmosphere over and above the classical bombast of that period.
Eno’s definition, on the other hand, was more conceptual, in that Eno was imagining music being played at airports that would add to the ambience of the environment, allowing a contemplative space where melody or rhythm or volume would not force or compete with the listener's attention. You could tune in, or tune out, it was up to you.
Of course there are other definitions of ambient music, and since Eno’s 1978 album, the term ambient has broadened to include many styles of music, including those that would contradict the definition of ambient that we have already discussed. There is nothing wrong with this, it just depends on your particular taste and preference.
For me, and the ambient music I like to create, ambient music is a set of sounds that emphasise a certain quality of stillness, of silence, that allows space for a listener to just be, instead of imposing on or reinforcing his/her/their ego. Ambient music then is an opportunity to let go and drift, to transcend or dissolve, for your whole being to be illuminated and float as a momentary here-and-now presence without linear boundaries.
I can sum this up, quite simply: the purpose of ambient music is to miss the mark. For when we hit the mark that we created and aimed for, the music somehow loses it's ambient quality and becomes something defined. Something defined is something known. We can then name it and compare it to what we already know. So then its elusive, transportive quality is lost. The listener is not transported or transcended beyond themselves. This ambient quality cannot be nailed down, and this is what makes this genre of music so fascinatingly simple yet hard to create. I don’t always miss the mark, as I do like to create music that is melodic or is supported by rhythms or beats. But when I do miss the mark, like a wonderfully composed haiku, an undefinable essence has been expressed, which I cannot put my finger on. And to me, that is the way it should be.