Students love playing with these simple musical instruments that cost a penny or so to make. They will build and design two different horns; one that is similar to an oboe and one like a medieval bladder pipe. Then they can experiment to make them play different volumes and tones as their team works with variables and controls. Students can research medieval history or the mathematics behind musical scales if they wish to refine their instruments. The vibrating parts illustrate the science of sound waves and other waves too.