67．In the twenties，jazz became the hottest new thing in dance music, much as ragtimehad at the turn of the century，and as would rhythm and blues in the forties，rock in the fifties，and disco in the seventies．

(特殊结构much as…and as…——就像…以及…一样)

20年代，爵士乐成为舞蹈音乐中最热门的新事物，正如世纪之交流行的拉格泰姆音乐，以及40年代节奏与布鲁斯，50年代摇滚乐，和70年代迪斯科将会流行一样。

分句1. In thetwenties，jazz becamethe hottest new thing in dance music,

分句2. much asragtime had at the turn of the century

分句3. and aswould rhythm and blues in the forties，rock in the fifties，and disco in the seventies．

1和2嵌套

2和3并列

2是1的补语。2中包含much as…and as的并列结构。