RADIO / Riding a Hitch: Robert Hanks on the morality of film and The Lovesong of Alfred J Hitchcock

This week, in its ceaseless round of ethical ambulance-chasing, The Moral Maze (Radio 4, Thursday) arrived at on-screen violence. For once, the assorted mavericks, and kindly Michael Buerk, were of one mind: they felt that watching violence on screen corrupts, and witnesses who dared to differ - like the film critic Alexander Walker - were given a rough ride.

Edward Pearce, for instance, apparently believed that anything that might affect even the most weak-minded, unbalanced member of society should be banned. (So bang goes 90 per cent of Western literature, eh?) He taxed Walker with living in an unreal world, because he spent his time watching films - an accusation that rings particularly hollow coming from a man best known as a parliamentary sketch-writer.

But only one witness mentioned the corrupting effects of radio plays, and only in passing, leaving Michael Buerk to wonder at the end why nobody had said more about it. The answer is, surely, that radio can rarely be as graphic as television or film, which makes copy-cat crime difficult. To properly understand violence on the radio you must know something of what violence looks like in the first place; television offers diagrams that even the innocent can follow. How can radio parallel the effect of the screen?

That question was answered with surprising effectiveness by The Lovesong of Alfred J Hitchcock (Radio 3, Sunday), a 'film for radio', written by David Rudkin, directed (meticulously) by Philip Martin, and featuring a brilliant central performance by Richard Griffiths, a strangulated, rumbling 'cockney baroque that never was'. The issue here was not so much how far watching films can corrupt, but how far making them can.

The title reference was not entirely gratuitous - we returned to Eliot in a dream sequence in which Hitchcock wanders through a graveyard, muttering 'Who would have thought Hitchcock would have undone so many?' Then again, Eliot was only one of the presiding deities of modernism to whom Rudkin paid homage (or in film-buff speak, hommage). In scenes depicting early childhood and education at the hands of Jesuits, there were echoes of Joyce; but mostly, Hitchcock's God was Freud - one possible alternative title would have been 'Dial M for Mother'. There are constant images of mothers and emasculation - 'I have no cock,' the director announces, inviting his scriptwriter to call him Hitch.

This scriptwriter was a composite figure, appearing throughout the play at a kind of abstract script-conference - containing at various points allusions to Rear Window, Strangers on a Train, Psycho and Vertigo, as Hitchcock ran through a hundred visions and revisions, coming up with obsessive images of blondes and sex for the writer to incorporate into the story.

What was most impressive was the way the play used film-making vocabulary in two ways. First, metaphorically, by describing shots through the camera's own commentary (spoken by Michael Fitzgerald). At times, these reproduced more closely than you could have imagined Hitch's extraordinary power of projecting psychology in his films - as if a magic lantern threw the nerves in patterns on a screen. (One beautifully evoked crane shot, in which the camera swept down and across a studio, cunningly recalled the moment in Notorious when the camera plunges down from the ball-room ceiling and swoops in to the key concealed in Ingrid Bergman's hand.)

The play also used a film vocabulary literally, adopting the terminology of flashbacks and cutting away to convey shifts in time and focus. At one point, the camera voices the direction: 'Obscure'. And here the listener thinks: you're telling me. Because for all its felicities, this was not an easy play to follow and in the end, like Hitchcock himself, not easy to like. But, also like Hitchcock, it knew how to force your attention; and perhaps we shouldn't ask for more than that.