"Sunday," said a British theater operator last week, in what had to be regarded as a masterpiece of understatement even for Britons, "is regarded as the difficult night in cinemas." The specific difficulty was the effect that a U.S. rock-'n'-roll movie was having on Britain's notorious teen-age delinquents, the Teddy Boys. Scarcely a week goes by without some headline proclaiming the latest exploits of the "Teds.'' But nothing before had sparked them to the frenzy induced by the gross tick-tock of Rock Around the Clock.
In a murky section of London that takes its name from the long-departed Elephant and...