This - what exactly shall I call it? - John Cage happening is based on a seminal concept in music: you can hear it or you cannot.

Rests, the absence of sound, have existed in music since the beginning. Initially they were used to signify a pause, a breath, a comma, as it were, in musical phrasing. Gradually, they were used for rhythmical purposes, emphasizing a moment in which a musical beat should be, but was not, syncopation, if you will. By the time of Anton Bruckner's great symphonic pauses, they had developed a new meaning, a stage direction of sorts that told the listener, exit one important idea, be ready for the entrance of the next.

Essentially, until the 20th century, rests, pauses, or silences of whatever ilk, were not musical utterances, rather the absence of same.

[Those of you who have visited this page before will have noticed that I have inserted an new video.  The original video has been removed from YouTube by the BBC due to copyright issues. There is a delicious absurdity here that Cage, above all others, would have relished.]

Shortly after the turn of the last century, an approximate date coinciding with the end of the Romantic period, composers found themselves on the horns of a dilemma. They could neither go forward nor back. For hundreds of years, music had been ruled by harmonic progression and the rules of counterpoint. From contrapuntal music, the rule of one principal voice, the melody, evolved, but the elemental harmonic structure and the rules that governed melodic motion were not abandoned, merely adapted to support the newly crowned king of music, melody. Composers then took melody from its simpler forms through increasingly complex formal structures and modulations to the ultimate almost unending melodic journeys over ever shifting harmonic sands.

But the basic building blocks of music continued to be what is known as traditional harmony. Tonic, dominant, sub dominant relationships and modulation through the circle of fifths, with an occasional nod to the relative minor, never ceded control over their domain, even in the most extreme cases in which tonality, as the world knew it, was stretched to and beyond its breaking point.

The young geniuses of the newly born 20th Century wrote the most gorgeously romantic music imaginable, huge canvases employing huge orchestras, sometimes in conjunction with chorus, indulging themselves in an orgy of everything that came before until they realized that they were building towers, skyscrapers on ancient and increasingly meaningless foundations.

Arnold Schoenberg, father of Atonality, wrote his Gurrelieder in the years between 1901 and 1911. The prelude to Part I of this great work follows.

Sir Simon Rattle conducting the Berlin Philharmonic Orchestra