Jazz music, developed by African-Americans in the late 1800s, allows performers to freely express their emotions and musical skill. Instead of just playing the melody, jazz musicians improvise different tunes using the same chords. The peak of jazz music came in the 1920s, known as "The Jazz Era." This period produced musicians like Louis Armstrong, Benny Goodman and Duke Ellington. These musicians later created the "big band" sounds of the 1930s. Different styles of jazz developed in different cities, such as New Orleans, Chicago, New York and Kansas City. Composer George Gershwin brought jazz into the world of classical music with pieces like "Rhapsody in Blue."
爵士乐是十九世纪末期由非裔的美国人发展出来的。它让表演者自由地表现他们的情感和音乐技巧。不仅演奏旋律，爵士音乐大师用同样的和弦即兴演奏出不同的曲调。爵士乐的高峰期出现于二○年代，该时期被称为「爵士年代」。这个时期创造出来的乐手有阿姆斯特朗（Louise Armstrong），古德曼（Benny goodman）和埃林顿（Duke Ellington）。这些乐手稍后都创造了三○年代的「大乐团」之音。在不同的城市也孕育出不同的爵士风格，像是纽奥尔良、芝加哥、纽约和坎萨斯市。作曲家盖希文（George Gershwin）更以像「蓝色狂想曲」这样的作品，将爵士乐带入古典音乐的世界里。
