In the 1950s, the American vocal group the Platters was the only major act to appeal to teenagers and their parents in equal measure. They had planned it that way or, at least, their manager, Buck Ram, did. When he was asked about their popularity, he didn't say, "They're going to be bigger than Elvis": he said, "They're going to be bigger than Louis Armstrong!" The Platters sang standards and new balladsslickly and professionally in evening wear but there was a gentle beat to everything they did