In 1956 the management of radio stations reeled back from the TV screen like so many blacksmiths confronted by a horseless carriage. Or like hand weavers threatened by the flying shuttle. Surely they were doomed. Surely their medium would become an anachronism.

But catastrophe somehow failed to befall them. Instead, radio has enjoyed an astonishing boom with many stations earning larger profits than the major channels. In economic terms at least, the medium has gone from strength to strength.

Many factors have contributed to this apparent paradox. First of all, there was a technological breakthrough. Just as the hand-held transistor feed radio from the lounge room and kitchen.

And while TV was getting involved in the heavy costs of variety and drama production, radio had reduced its programming to what’s variously described as Top Forty or Fat Fifty. The vast record libraries were no more, having been replaced by a small shelf of 45s.

Having established itself as a juke box, radio then became a phone box as well. For it discovered that housewives were a lonely, alienated group, yearning for some form of social involvement.

Given the flexibility of audio tape, radio production costs are negligible and permit a higher degree of formal innovation than TV. For example, where TV necessitates set building and costume design, the radio audience can simply imagine them. And a cast of thousands is as close as the sound-effects library.