Evolution or Revolution

I was struck yesterday by experiences which raised for me the question whether change in worship style is best achieved by evolution (i.e. gradual, incremental change) or by revolution (i.e. instant, dramatic, global change)?

I guess the answer is probably that in some contexts evolution works well, and in other contexts revolution works well.

In the background to my mentioning this question is that in some places there is an associated question: does the situation provide the time for evolution to take place or must revolution occur before the church doors are shut?