Every artist knows the key to a successful performance - always exit the stage leaving the audience wanting more. There will be no encore after the curtain falls on Alan Greenspan's 181/2-year tenure as head of the US Federal Reserve Bank at the end of this month. But the former professional musician with a strong passion for jazz will probably be heading into retirement with plaudits from a generation of prospering Americans ringing in his ears. A few bum notes aside, Mr Greenspan's spell as the nation's most powerful economist has been largely successful, though analysts say it will be several years before his true legacy is known. His tough decisions over interest rates and slick handling of unstable US financial markets created a sustained period of economic growth, pushing home ownership to record levels and swelling pay packets like never before. Yet the millions of middle-class Americans who reaped the benefits of Mr Greenspan's economic policies are mostly oblivious to the intriguing private life of the soft-spoken 79-year-old, whose fondness for music and baseball, and a wife 20 years his junior, belie his public facade as a dull accountant. 'His public demeanour is very guarded and dour and his past is not immediately evident,' said biographer Justin Martin, author of Greenspan: The Man Behind the Money. 'But here's a guy who's had a very interesting life and been a professional musician. And people maybe forget that it's possible to be passionate about economics. Behind the scenes he loves poring over this stuff.' As a result, Martin does not believe that Mr Greenspan's retirement will be particularly quiet. 'He's not much of a hobbyist,' he said. 'He's a person who's most alive when he's working. He's an old man but he has knowledge, and I'd lay odds he'll be called upon again. Social security and health care are a mess, and I can see him appointed to some presidential commission to help sort it all out.' Mr Greenspan was enchanted by music at an early age, a passion he has maintained throughout his career alongside his love of the Baltimore Orioles baseball team. As a high school student, he would spend summers listening to Glenn Miller records with his cousins at their beach house in New Jersey. Even then, he was a ladies' man. 'As I recall, during the summers he had more dates than me,' said Wesley Halpert, Mr Greenspan's cousin. 'He always selected girls that looked like his mother.' After high school, and realising that he was never going to become a professional baseball player 'because I couldn't hit a curve ball very well', Mr Greenspan was accepted by the renowned Juilliard Music School in New York. He spent two terms studying the saxophone and clarinet before dropping out to join the touring Henry Jerome swing band with, among others, the younger but more talented Stan Getz, who went on to become a jazz legend. The pair earned US$6 a week. 'Stan was instrumental in my deciding that music wasn't going to be my profession either,' Mr Greenspan once admitted, 'because I had to sit next to that guy and listen to what in the world he was doing, and I'm saying, 'How in the world does he do it?'' During that time, Mr Greenspan did figure out what he was going to do. He would spend breaks between performances in libraries and would read books on economics avidly. Once embarked on his chosen career, his rise was swift. He became a confidant of the noted anti-government philosopher and writer Ayn Rand, and in 1954 set up an economic consulting firm, which he headed for 30 years. He served as an adviser to presidents Richard Nixon and Jimmy Carter, and was appointed chairman of the Federal Reserve by Ronald Reagan in 1987. In his office at the bank, Mr Greenspan has portraits of the four presidents he served under, Reagan, George Bush senior, Bill Clinton and George W. Bush. Greenspan is married to NBC foreign correspondent Andrea Mitchell, his second wife, whose autobiography published last year paints her husband as a highly intelligent, sensitive and unassuming man, with a well-developed sense of humour. She recalls that their first date was dinner at his favourite New York restaurant, to which she arrived late, wet and dishevelled after a dash through Manhattan in the snow. 'We connected, talking about music and baseball and our childhoods. I found this shy man known for convoluted explanations on economic trends to be funny and sweet and very endearing,' she said. Dinner guests at the Greenspans' home in New York are frequently treated to a rendition on the jazz piano, providing there is no baseball game taking place. 'It's a close call whether the house will be filled with Vivaldi or the Orioles,' Mitchell said. It proves that, two months short of his 80th birthday, Greenspan is still living up to the inscription beneath his graduation photograph in the George Washington High School yearbook of 1943. 'Smart as a whip and talented, too,' it said. 'He'll play the sax and clarinet for you.'