John Cage Uncaged, BBC Symphony Orchestra, Radio 3

Although 4'33" is often referred to as John Cage's "silent piece" - the composer himself used the term - part of its point is to demonstrate that the concept of silence is at odds with reality. Visiting Harvard's anechoic chamber, Cage noticed that in this supposedly silent space he could still make out two faint, constant sounds. Afterwards, he was told that the higher pitched noise was his nervous system, the lower his blood pumping through his veins. From this, Cage concluded that we are all making music all the time - we just don't know it.

In 4'33" the nominal performer, or performers, don't perform for four minutes and 33 seconds (with breaks in between the three movements), while the audience listen to whatever sounds are happening around them. In the concert hall this will generally include the hum of air-conditioning systems, the shuffling of fellow audience members and perhaps traffic noises. Last night's performance by Lawrence Foster and the BBC Symphony Orchestra - a rare orchestral outing for a piece that is usually performed by a soloist - included some spectacular bouts of coughing in between movements, some unexplained giggling, and in the live radio transmission, an exciting variety of kitchen noises: among them, some quite beautifully realised boiling pasta - the whimpering of small children in quest of milk and attention, and the buzz of what sounded like a pizza delivery moped.

It is arguable that this was not, as advertised, the first broadcast of 4'33" on British radio. I heard what claimed to be a transmission on Radio 3 some years ago. On that occasion, however, the presenter explained that automatic override systems would cut in if the station was silent for too long; and so a recording of Cage was played simultaneously with a recording of a more conventional piece of music. For last night's concert, however, the override systems were switched off.

Was there really any point, though? That the event had a tension and interest for those attending was clear from the amount of coughing, and the enthusiastic applause. Listening at home, though, the impact was dissipated: having the radio on but almost silent is not really different from having it on with the volume turned down. The piece needs the chemistry of performer and audience and the relatively formal setting of a concert-hall to succeed. But conventional music can dispense with the concert-hall - you can always whistle Beethoven's Fifth, or hear a record; 4'33" is unique in the way it requires formal structures to give it meaning. In the end, the message of 4'33" is: turn the music back on.