It's how you remix. You take existing songs, you chop them up, you transform the pieces, you combine them back together again, and you've got a new song, but that new song is clearly comprised of old songs.
过程是：你把现有的歌曲， 截成小段、 变换这些片断， 最后再结合起来， 你造出了一首新歌，但这首新歌 很明显是老歌曲组成的。