What does a perfect fifth sound like

1. What is a perfect fifth in music?
2. Why does a perfect fifth sound good?

What is a perfect fifth in music?

In music theory, a perfect fifth is the musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, or very nearly so. In classical music from Western culture, a fifth is the interval from the first to the last of five consecutive notes in a diatonic scale.

Why does a perfect fifth sound good?

The perfect 5th has the simplest form with the fewest peaks and valleys, making a smooth sounding tone. More peaks and valleys in a tone we will hear as a dissonance or "grinding" sound. The only thing smoother than the 5th would be an octave, or 2:1 ratio.