Announcement, announcement! I invite you to participate in a back2school contest - a musical & scientific one! The question In the following video, artist Rico Loop is beat-boxing and playing bass, melodica, as well as a water bottle . The question is: How much water does Rico Loop drink each time he changes pitch? At 0:19, he blows a pitch without looping it. Then, he loops sounds at 0:23, 0:40, 0:53, and 1:02, when he's done drinking. So, you are looking for 4 quantities of water. You may give your answers as proportions instead of absolute values. Prize I will be offering a special prize to the person coming up with the best answer - and explanations, of course! Please, e-mail me your answers, or post a comment. I'm going to give a few hints in the next couple of weeks... Stay tuned.