When you feel tired, how do you relax ? Drink coffee, take a bath ,do so-me exercise ,or play some music and dance ? For dance music fans and nightclub lovers, the world famous English DJ ( disco jockey ) Sasha will bring them the world’s finest dance music. He is coming to Guangzhou, Beijing and Shanghai on November 18-20 as part of his world tour in support of his new CD. One of the main roles of music has always been to go with dancing. But, today’s dance music is very different from the past. The history of dance music goes back to the 16th century. In the Renaissance (文艺复兴) and Baroque (巴洛克) periods in Europe, rich people were expected to be able to dance at social events. Each type of dance gave rise to its own form so music. During the 18th and 19th centuries the most popular dances were the Waltz and the Polka (波尔卡舞) .In this period, dances were often written for the concert hall. For example, symphonies (交响乐) would have a waltz movement, and piano pieces were sometimes in waltz or polka. In the 1970s, dance music moved into new places called discos. The music was faster ,had more bass and started to become more electric. Disco music began to develop in the US and around Europe .By the 1980s the music became much faster and even more electronic. In the1990s clubs took over discos. DJs mixed other people’s music .Club dance rhythms (韵律) became a major part of popular music .Club dance music has different forms, including drum and bass (低音乐器) ,hip-hop ,R & B.It makes use of technology and DJs play a bigger part in spreading the music.