Today's program consists of the Men's choirs, Poetry reading, original, Poetry reading from one of the set poems, and children's dance. (See The Goodies, "Eisteddfod from the Welsh. Eistedd, bored. Fod, stiff.") -- Anon Guest
Colony worlds, once cut off from their progenitor planet, have to deal with what they've got. B'Nar took everything nerd-related with them owing to the fact that it was settled by genetic engineering companies and their nerdy, nerdy staff. And their equally nerdy families. The assembled Greater Deregulations took their might-is-right moralistic entertainments made to preach to the choir. Britania gathered up everything that Britain had ever made.
Once there, and the wormhole closes, all communication ends. Whatever a colony has is what they use as a base for the initial derivative works. For a century or so, the colonists essentially pump out a gigantic amount of fanfiction with no fear of litigation from the originator.
Some didn't believe that entertainment was worth taking along. Thus, the derivative works are more or less based on collective recall and fan-made fixes. Acted out, mutated, retold, and rewritten by the performance. And then all of these mutated celebrations that became classics on other worlds, are taken back and shown to those who actually have memories of the original.