Those for whom the term "ambient music" conjures up crystals, dream-catchers and the pong of ineffective tea-tree deodorant can be forgiven - many crimes against the genre have been committed in the name of the New Age.
But it's unlikely Brian Eno had universal truth in mind in 1978 when he coined the expression to describe the first of four albums carrying the ambient label.
In the liner notes to 1979's Ambient 1: Music For Airports, Eno said of his concept: "Ambient music is intended to induce calm and a space to think . . . It must be as ignorable as it is interesting."
His intention was to draw a distinction between the overly stimulating musak that had invaded public spaces, and his unobtrusive "environmental" music that "accommodated many levels of listening attention without enforcing one in particular".
Eno hoped that his minimalist experiments would be continuously looped as sound installations. In fact, Ambient 1 was used in passenger waiting areas of some airports.
Through a process of phasing tape loops of different lengths, Eno created a four-track album of serene and extended sonic landscapes.
The first of the four tracks (and longest, at 17 minutes) employed acoustic and electric piano, and synthesizer, with a single piano melody coming together at different intervals with the other instruments.
A similar approach was taken on track two, where three separate "aaaaaaaah" vocal lines converged and diverged dependent on the length of each loop.
Tracks three and four continued both the method and the mood, with synthesizer and vocals-as-instruments forming environments that could be traversed in a state of either meditative focus or blissful inattention.
Eno's goals were met via the illusion of repetition; the subtle variations in timing ensuring musical events were not repeated. In this way, Ambient 1 offered up surprises, and went on to influence all that followed in the ambient field.
