The historian Dominic Sandbrook is known for sweeping surveys of post-war British life and politics. In Let Us Entertain You, a four-part series, he looks at the impact of British popular culture over the past century.The first episode (4 November) explored the notion that cultural industries have replaced old-fashioned manufacturing by mimicking its packaging and marketing techniques. He started somewhere quite unexpected, telling the story of a 17-year-old Birmingham lad and an industrial accident. On his last day in a steelworks, amateur guitarist Tony Iommi caught his hand in a metal press and lost two fingertips on his fretting hand. Undismayed, he fitted two leather thimbles to the damaged fingers and went on to form the band Black Sabbath.Black Sabbath created heavy metal, which be