Why do certain pairs of notes sound better than others?

You don’t have to be a musician to know when music sounds bad. But what is it, exactly, that makes music sound good? Turns out it’s all in the numbers. The combinations of notes we find pleasing are based on simple ratios.

In this lesson, students learn how the notes plucked on stringed instruments are mathematically related. By calculating the ratios of string lengths, students explore the relationship between notes that sound good together — and also those that don’t. Math and music have more in common than you might think!

- Measure string lengths and calculate the ratios for different notes in a major scale
- Apply fraction division to calculate the length ratio between any pair of strings
- Explore the relationship among string lengths, ratios, and sound quality of simple harmonies

- Rulers
- Colored pencils

The Piano Guys, One Direction