填空题

Jazz began in the early 20th century as a kind of music of black Americans. It was (36) for singing, for dancing, and for entertainment and atmosphere at parties or social (37) .
Jazz has continued to develop and has produced some of the United States’ leading singers, instrumentalists, and (38) . Today, it’ s (39) by many to be America’ s art music. It has also (40) almost every other kind of music in America, Europe, and even the (41) .
Jazz represents a (42) of musical elements from Africa and from Europe. Jazz uses some European ideas of (43) and melody, but the rhythms are more African in origin. And Jazz is polyrhythmic, (44) .
The most important feature of Jazz is improvisation. (45) . Jazz musicians have learned to improvise so well that they can make up excellent melodies as they play. A good Jazz player seldom plays anything the same way twice. (46) .