Elaboration on title: What would most likely be the first explosive compound that some individual would create if they were just mixing together random things they had available? I'm not talking about our world history, where it was the discovery of black powder in China about 1200 years ago. I'm talking about some arbitrary race somewhere in the universe; what would most likely be the first explosive they develop, combining anything organic they could get? Would it be black powder? Nitroglycerin? Nitrocellulose?
(Keep in mind that this question is coming from someone who isn't really a chemistry nerd :p)