What is world music and why does it exist?

It is very difficult to define world Music as it isn’t actually a `true` genre. One way to consider it is as the global music, music which is globally produced and distributed. However whilst this would seem the most logical answer it is not in fact the one that places such as HMV and other music distributors use. Quite often the category `World Music` contains music from non-English countries with foreign language as its basis. This is not a strict definition of course as some foreign language music belongs in more clearly defined genres. World Music as a genre essentially exists to describe any indigenous local music which has been distributed worldwide and doesn’t fit into any of the other genres. Therefore it would seem that World Music is in fact local indigenous music which is globally distributed, ironic really.