Slides used to present Europe Code Week at the Scratch Conference in Amsterdam. Something strange happened during the presentation when a strange music was heard in the conference room. The phenomenon is documented by a video recorded unintentionally by the GoPro of one of the attendees: https://youtu.be/BO9x6XImDfQ The strange tune is hidden in slide 14. You cannot hear it from SlideShare, but you can download the presentation and launch it on your PC to see what happens...