In Musical Instruments, inhabitants of Mammoth Island invite a visiting inventor to a concert of mammoth proportions! Instead of playing instruments, the islanders rely on musical mammoths for entertainment. After the performance, which includes a rather dangerous stampede, the inventor shares what he knows about musical instruments with a young islander named Olive and her friends. Sound waves of different frequencies result in different pitches, and instruments of those different pitches are combined to produce music. The islanders learn the principles behind various wind, string, brass and percussion instruments and the various sounds they produce. And the result is music to their ears!