I'd say read the FAQ, except it ain't done yet. Nope, instrumental music does nothing. Doug has several snippets in his helmet which I always intended to use for comedic or dramatic effect -- cartoon sound cues, dramatic stings, stuff like that -- but I never got around to using it in-game, and it hasn't been appropriate yet in-story. The Iron Chef theme is as good an idea as any I've seen in a while...
-- Bob
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There is no spork.
-- Bob
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There is no spork.