Indeed, and the connection here to Dawkins’ concept of “memes” could certainly be expanded upon. In culture, however, you do (at some level) have intelligent designers – musicians, writers, directors, labels, A&R people are (often? usually?) trying to “succeed”, and so their changes aren’t random. The weird thing is how often the important developments have a certain aspect of randomness, or at least unexpectedness, about them. Sometimes people know they’ve really done something special, but quite often they’re totally surprised by the impact they had. And sometimes it can take quite a quite for that impact to be understood. I’m sure that a lot of the musicians that recorded in the 20s and 30s didn’t expect their work to still be selling and culturally important 3/4 of a century later, regardless of their hopes that it would sell well in their time and bring them some fame.

Just to insert one of my little obsessions: that description of “they take little bits of things from here and there and put them together in unexpected combinations that seem new and original” is also a good summary of evolutionary bricolage.