Mash-Ups in Fashion, Music & Literature
When I think about mash-ups, I can't help but think about Julia Kristeva and her notion of intertextuality.
The term has been used in many, many different ways since she first coined it, but, quite generally, she was using it to talk about literature and the way that it exists within not only a network of language but a network of texts. Every text, even something you wrote on a sticky note, is in dialogue with the entire linguistic system - you've just selected a few words from that system. Those words, of course, are weighted with meaning: they have a long history of being used by lots of other people, for lots of different purposes - both constructive and nefarious.
Now a literary text - something that's trying to assert or achieve the status of a cultural object that deserves a reader's consideration (something more refined than your sticky note) - is part of a network of language and also a network of previous texts. Kristeva was very interested in how it is that the meaning of a piece of literature is produced in the mind of a reader, who cannot help but situate their understanding of that text in a larger context, one that includes what they've read before and what the writer is both self-consciously and unconsciously referencing.
If you think about it, the process of writing anything could be described as the process of sampling.
Some authors are far more self-conscious about this process than others. I wrote my doctoral dissertation about literary modernism and so I became very familiar with T.S. Eliot's The Waste Land, a poem infamous for its intertextuality. Eliot's literary and historical references were so numerous and so intricately interwoven that he was prevailed upon to provide footnotes for later editions. Nowadays I don't believe you can find an edition without the footnotes, which themselves have become the subject of detailed literary analysis. Even though I was a big fan of Public Enemy at the time, it didn't occur to me that what Eliot was doing in his "high modernist" masterpiece was not all that different from what hip-hop artists were doing with recorded samples - creating multilayered, multivalent texts that engage with the past as they try to grapple with the present. (You can find out a bit more about my continuing research on The Waste Land here)