Jazz has been called America''''''''''''''''s classical music, and for good reason. Along with the blues, its forefather, it is one of the first truly indigenous musics to develop in America, yet its unpredictable, risky ventures into improvisation gave it critical cache with scholars that the blues lacked.

　　爵士乐有充足的理由被叫作美国的古典音乐。与其鼻祖布鲁斯乐一脉相承，爵士乐是最早的一种真正的在美国发展进化的、本土化的音乐，而其玄妙莫测的、充满冒险精神的即兴演奏又给了它布鲁斯音乐所没有的学者级别的评论和收藏。

　　At the outset, jazz was dance music, performed by swinging big bands. Soon, the dance elements faded into the background and improvisation became the key element of the music. As the genre evolved, the music split into a number of different styles, from the speedy, hard-hitting rhythms of be-bop and the laid-back, mellow harmonies of cool jazz to the jittery, atonal forays of free jazz and the earthy grooves of soul jazz. What tied it all together was a foundation in the blues, a reliance on group interplay and unpredictable improvisation. Throughout the years, and in all the different styles, those are the qualities that defined jazz.

　　最早先的爵士是种跳舞音乐，由摇摆大乐团（编者注：Swing是种早期爵士乐风格，如猫王就大量演绎此种风格的作品;而Big Bands是指由数名爵士演奏者组成的专门伴奏的乐队）演奏。很快地，跳舞元素便从音乐背景中慢慢消失，而即兴成为此种音乐关键的元素。随着门类的发展和进化，爵士乐分离成数种不同的风格，比如从快速地、重拍节奏的比－波普乐和慵懒的、和声柔美的冷爵士乐，到晃动不安的、冷不防出现无调音律的自由派爵士以及灵魂爵士中那朴实无华的低音节奏。真正将种种风格牢牢绑在一起的是布鲁斯乐的根基、乐团成员间交替演奏的信任和玄妙难料的即兴。这些特质贯穿了多年以及所有不同的风格，并最终定义了爵士。