limits and boundaries: wikiality

An interesting and problematic article from Wikipedia on musical improvisation (archived version in case of changes).

Improvisation can be structured, with certain rules constraining the improvisation (for example, "make up a song about bicycles", "use these chord changes", and so on), or can have no such constraints.

As I wrote in a previous post there’s an assumption that structure comes from outside, and that ‘limits’ carry out that structuring. Additionally, the Wikipedia entry implies that improvisation without constraint results in a performance with no structure.
I don’t believe that this particular understanding of ‘structure’ is helpful to the practice of improvisation. Nor do I have much affinity with the desire for this ‘structure.’ As for alternative definitions of ‘structure,’ I’ll save that for a more extensive post….

A couple of other things about the article. How is it that the writers can state that improvisation has been “an integral part of music since the beginning of music,” yet suggest that improvisation is distinct or separate from the “conventional approach” to musical performance? I also wonder if improvisers would agree that what they do is play in an “offhand manner.”