@Glenn_Irish Oh yes Glenn, I was thinking about music (but your idea about lyrics is a good one!)… There are countless (sometimes hidden and sometimes purposely evident) insertions from one previous melody into another composition, variations, sometimes they re-use same complex chord sequences that references previous works.
Take for example music from the composer Mike Oldfield using secretly melodies of “The Songs of a Distant Earth” in his album “Amarok”; or Tubular Bells I, II and III and Music of the Spheres; or Enya’s compositions “On my way home” and “Sail away” (there she re-uses both melody and lyrics).
The extreme of this technique would be things like the direct “self-sampling” like Michael Cretu did on most of his albums, in his electronic project called “Enigma”, if we talk about the electronic/pop music genre. And the list goes on…
Also non-copyrighted music is often used, in the style of Tchaikovsky (he included parts of the beautiful “La Marseillaise” on his composition “1812”).
Self-reference may be a valuable artistic resource, and it is quite often a very effective one.
@Takafumi I’m not sure about that one, it certainly has many similarities… but let me tell you that a couple of times I’ve confused (in my first days listening to Key’s music) music from Tomoyo After with music from Clannad/After Story. I will re-check them later…
@Inuconandoyle Thanks to your commentary I will have to relisten the entire OST of Little Busters (I’m serious)
Anyway, it is good excuse to re-visit good, memory trigger, music. Isn’t it?