[originaltext] At the beginning of the 20th century, a new music called jazz

At the beginning of the 20th century, a new music called jazz was born in New Orleans. It was a kind of music in tended to make people happy, but it was not so much a kind of music as a style of playing. The New Orleans musicians learned to work together to produce a relaxed beat.  The beat is so powerful that the listeners can not help dancing.
    The best and almost the only place to hear the original New Orleans jazz is in Preservation Hall in the French Quarter of the city. There, seven different hands, made up mostly of very old men, play the old music each evening. Some of the people in the audience are tourists, but most axe serious music lovers who are willing to spend time sitting on plain wooden chairs and benches, and even on the floor. The musicians play the music they want to play, but the audience can ask for a particular song if they are willing to pay for it. Traditional songs cost one dollar and all others cost two.
     Old-style New Orleans jazz is in danger of disappearing because the players are getting old. The music did disappear once before, when people lose interest in it and the musicians had to make their living doing other things. But in 1938 the current jazz revival began, when music historian William Russell found a famous trumpet player Bunk Johnson working in the field and brought him back to New Orleans to play, When Preservation Hall reopened in 1961, the old music finally had a place to live again, and its popularity has grown ever since.