George Gershwin, born in 1998, was one of America's greatest composers. He published his first song when he was eighteen years old. During the next twenty years he wrote more than five hundred songs.

Many of Gershwin's songs were first written for musical plays performed in theatres in New York City. These plays were a popular form of entertainment in the 1920s and 1930s. Many of his songs have remained popular as ever. Over the years they have been sung and played in every possible way — from jazz to country.

    In the 1920s there was a debate in the United States about jazz music. Could jazz, some people asked, be considered serious music? In 1924 jazz musician and orchestra leader Paul Whiteman decided to organize a special concert to show that jazz was serious music. Gershwin agreed to compose something for the concert before he realized he had just a few weeks to do it. And in that short time, he composed a piece for piano and orchestra which he called Rhapsody in Blue. Gershwin himself played the piano at the concert. The audience were thrilled when they heard his music. It made him world-famous and showed that jazz music could be both serious and popular.

    In 1928, Gershwin went to Paris. He applied to study composition (作曲)with the well-known musician Nadia Boulanger, but she rejected him. She was afraid that classical study would ruin his jazz-influenced style. While there, Gershwin wrote An American in Paris. When it was first performed, critics (评论家)were divided over the music. Some called it happy and full of life, to others it was silly and boring. But it quickly became popular in Europe and the United States. It still remains one of his most famous works.

    George Gershwin died in 1937, just days after doctors learned he had brain cancer. He was only thirty-nine years old. Newspapers all over the world reported his death on their front pages. People mourned the loss of the man and all the music he might have still written.

    It was one of those terribly hot days in Baltimore. Needless to say, it was too hot to do anything outside. But it was also scorching in our apartment. This was 1962, and I would not live in a place with an air conditioner for another ten years. So my brother and I decided to leave the apartment to find someplace indoors. He suggested we could see a movie. It was a brilliant plan.

    Movie theaters were one of the few places you could sit all day and—most important —sit in air conditioning. In those days, you could buy one ticket and sit through two movies. Then, the theater would show the same two movies again. If you wanted to, you could sit through them twice. Most people did not do that, but the manager at our theater. Mr. Bellow did not mind if you did.

    That particular day, my brother and I sat through both movies twice, trying to escape the heat. We bought three bags of popcorn and three sodas each. Then, we sat and watched The Music Man followed by The Man Who Shot Liberty Valance. We'd already seen the second movie once before. It had been at the theater since January, because Mr. Bellow loved anything with John Wayne in it.

    We left the theater around 8, just before the evening shows began. But we returned the next day and saw the same two movies again, twice more. And we did it the next day too. Finally, on the fourth day, the heat wave broke.

    Still, to this day I can sing half the songs in The Music Man and recite half of John Wayne and Jimmy Stewart's dialogue from The Man Who Shot Liberty Valance! Those memories are some of the few I have of the heat wave of 1962. They're really memories of the screen, not memories of my life.

Human speech contains more than 2, 000 different sounds, from the common "m" and "a" to the rare clicks of some southern African languages. But why are certain sounds more common than others? A ground-breaking, five-year study shows that diet-related changes in human bite led to new speech sounds that are now found in half the world's languages.

More than 30 years ago, the scholar Charles Hockett noted that speech sounds called labiodentals, such as "f" and "v", were more common in the languages of societies that ate softer foods. Now a team of researchers led by Damián Blasi at the University of Zurich, Switzerland, has found how and why this trend arose.

They discovered that the upper and lower front teeth of ancient human adults were aligned (对齐), making it hard to produce labiodentals, which are formed by touching the lower lip to the upper teeth. Later, our jaws changed to an overbite structure(结构), making it easier to produce such sounds.

The team showed that this change in bite was connected with the development of agriculture in the Neolithic period. Food became easier to chew at this point. The jawbone didn't have to do as much work and so didn't grow to be so large.

Analyses of a language database also confirmed that there was a global change in the sound of world languages after the Neolithic age, with the use of "f" and "v" increasing remarkably during the last few thousand years. These sounds are still not found in the languages of many hunter-gatherer people today.

This research overturns the popular view that all human speech sounds were present when human beings evolved around 300, 000 years ago. "The set of speech sounds we use has not necessarily remained stable since the appearance of human beings, but rather the huge variety of speech sounds that we find today is the product of a complex interplay of things like biological change and cultural evolution," said Steven Moran, a member of the research team.