You may have heard of Kenny G, but what do you really know about jazz? Jazz is a genuinely American art form that has blossomed into a worldwide phenomenon. It is certainly much more than mere background music.

Jazz comes in a wide variety of styles, and has several defining features. The most important of these is improvisation. Jazz musicians do not follow a set piece of music note by note, but make up melodies and chord changes as they play. Such improvisation is based on a musician's creative impulses, and is often inspired by interactions with the other players or the audience. It is this energetic feedback and element of anticipation that gives jazz its incredible dynamism. A piece is never played the same way twice.

The originators of jazz were African-Americans in the early 20th century who fused African rhythms with European ideas of harmony and melody. Jazz's use of rhythm is unique in that it is “syncopated”; that is, the rhythm is irregular. Jazz is also polyrhythmic, which means many rhythms revolve around one basic one.

Another musical genre created by African-Americans, the blues, has heavily influenced jazz as well as rock and roll. About one third of jazz is in blues form with twelve measures in a song and uses ---blue notes,” the flatted third, fifth, and seventh notes of the musical scale.

Jazz has inspired everything from slang such as “cool” and “jazzy”; to dance styles such as tap and swing; to art forms such as filmmaking and beat poetry. Its dynamic nature and strong individual performers have also given rise to different branches of jazz.

Early jazz was centered in New Orleans and had trumpeter Louis Armstrong as its first great soloist. The '30s and '40s saw jazz's sound grow more forceful and invigorating, inciting people to dance. The master of this “big band” or “swing” style was Duke Ellington, thought to be one of America's greatest composers in any genre.

“Bebop” appeared in the 1940s. It introduced more complex melodies, harmonies, and rhythms, as well as more expressive drumming. In the late '40s, Miles Davis ushered in “cool jazz”' s smoother, more harmonic sound. The last of the classic jazz styles, “hard bop,” was more soulful, and sometimes borrowed from R&B and gospel themes.

Later strains of jazz include “fusion,” “bossa nova,” and “funk.” “Smooth jazz,” with Kenny G at its forefront, has proved the most commercially viable form of jazz, although purists scoff at its slick production and lack of improvisation. Regardless of the jazz you have been exposed to, a wealth of it still awaits you. In this era of boy bands, jazz reminds us of what a sublime and rewarding experience listening to music can be.

1. improvisation n. 即興演出或創作

2. impulse n. 沖動，興致

3. fuse v. 結合

4. measure n. （此指）小節

5. invigorating a. 令人振奮的

6. strain n. 家系、曲

7. purist n. 純粹主義者

8. sublime a. 卓越的

你也許聽說過凱麗·金，但是對爵士樂你真的了解多少呢？爵士樂是一種地道的美國藝術形式，它已經發展成為一種風靡全球的現象。爵士樂絕不僅僅只是背景音樂。

爵士樂以多種風格出現，具有幾種可用作定義的特點。其中最重要的一種是即興演出。爵士樂手不會按照固定的樂譜一個音符一個音符地演奏，而是在演出的時候自編旋律及變化和弦。這樣的即興演出基于樂手的創作沖動，通常是由與其它樂手或與觀眾間的互動激發起來的。正是這種充滿活力的回應和充滿期待的成分賦予了爵士樂不可思議的活力。一首樂曲絕不會有兩次相同的演奏。

爵士樂的創始人是20世紀初期的非洲裔美國人，他們將非洲的節奏融入歐洲的和聲和旋律的概念中去。爵士樂采用“切分”的演奏是很獨特的；也就是說，節奏是不規則的。爵士樂也是多重節奏的，即多種節奏圍繞一個基本節奏而進行。

非洲裔美國人所創的另一種音樂類型──藍調，對爵士樂和搖滾樂都有深遠的影響。大約有三分之一的爵士樂采用藍調形式，一首歌有12小節，使用“藍音”，即把第三、五、七個音階降半音（如Ｃ大調的Ｅ、Ｇ、Ｂ）。

爵士樂激發了各種靈感，如：從俚語中的“酷”和“奔放”兩個詞，到舞蹈風格中的踢跶舞和搖擺舞（即興爵士舞），以及電影制片和節拍詩等藝術形式。爵士樂富有活力的性質和有很強感染力的個人表演者也導致了不同流派爵士樂的產生。

早期的爵士樂以新奧爾良為中心，并有出色的首席獨奏者小號手路易斯·阿姆斯特朗。30和40年代的爵士樂的樂音變得更加強有力、更加振奮人心，把人們跳舞的情緒調動起來了。“大樂團”和“搖擺樂”的大師艾靈頓公爵，被公認為美國各種音樂類型中最偉大的作曲家之一。

“咆哮爵士”出現在20世紀40年代。它引入了更復雜的曲調、和弦與節奏，還有更富有表現力的爵士鼓。40年代后期，邁爾士·戴維斯開創了樂音更流暢、更和諧的“酷派爵士樂”。最新風格的古典爵士樂“硬式咆哮爵士”就更加熱情洋溢了，它有時還會從節奏藍調和福音書中取材。此后的爵士曲調包括“融合爵士樂”、“波薩諾瓦爵士樂”，以及“方克”。

盡管純粹主義一派嘲笑它的作品媚俗且缺乏即興創作，凱麗·金為先鋒的“輕柔爵士樂”卻證明了它是最具商業競爭力的爵士樂類別。除了你曾接觸過的爵士樂，它還有大量的爵士等待著你去發掘。在這個男孩樂隊當道的年代，爵士樂讓我們記起在聆聽音樂時，那種超凡而愉悅的體驗是多么美好。