How do pipes sound

Organ pipes come in all shapes and sizes. And each type has its own sound. How is it possible that an organ pipe (or a flute) makes a sound? And how can you influence the pitch and the sound color? That is a question for science, let us study some physics.

Note: The two pages (in Dutch) are two sides of an instruction sheet. It belongs to a new project, ‘The Organ Knights’. A project for three lessons in school, with a workbook, 6 podcasts, music, a special song about stops, and a teachers manual. It is almost ready in Dutch but not translated yet.