continuous mixing: A song to song mixing technique where the goal is to obfuscate the transition between the two songs such that a casual listener cannot immediately pinpoint when the transition occurred. This can involve the use of beat matching/alignment, phrase matching/alignment, content aware equalization and other technical elements as well as sensible song selection with regard to harmony (i.e. key changes that make musical sense).
So that's my starting point. Anyone else have an opinion? What is continuous mixing mean to you? Bonus question! When is continuous mixing an appropriate transition technique in playlist presentation? I'm starting with modern electronic dance music, but these techniques can certainly apply to other musics (speed metal? maybe. free jazz? probably not...)