And then he goes back to hell and then back up to heaven -goes back and forth between these two rhythmically very different concepts.

然后它回到了地狱,接着又升到了天堂,在这两种节奏非常不同的概念之间,来回往复

耶鲁公开课 - 聆听音乐课程节选

They both start with the letter D but they're very different concepts.

他们都是以D开头的,但却是截然不同的概念

耶鲁公开课 - 金融市场课程节选