I recently read an article that gave me food for thought. In a world were it seems that indeed nothing is new under the sun, why should lyrics be any different? I remember when I first came across the words: "contains an interpolation of... ". It was in the CD booklet of 2 Pac's Me Against the World.
And I was like, what is that? Sounds fancy. It was then I learnt that it was kinda like sampling lyrics or lifting a phrase or riff from another song. And now I've been noticing this technique of songwriting has become a growing trend.
To read more on this checkout the full length article on The Guardian: Copy-and-paste songwriting for a switched-on world.