Those looking for insight on all those Kikuta visual novels and original albums can now hear what the man himself has to say. He discusses the underlying themes of the visual novels and the concept behind the original albums plus more:

Square Enix Music Online :: Interview with Hiroki Kikuta (November 2009)

I hope everyone enjoys it. And hope it satisfies for you, Marcel, and thanks again for all your question suggestions.

Thanks Mr. X for linking the interview.

Quite lengthy but very interesting to read! Makes me want to listen to SD2 and Soukaigi again :)