Vibrations

Riddle: I shake, but unlike the strength of an earthquake. You can find me both high and low, usually out of control. I can be considered both good or bad, sometimes used for both happy or sad. What am I?

Answer: Singing Pitch.

Source: https://www.riddles.com/index.php/9069

I shake, but unlike the strength of an earthquake. You can find me both high and low, usually out of control. I can be considered both good or bad, sometimes used for both happy or sad. What am I? — Vibrations by Corey W v1.

Riddle: I shake, but unlike the strength of an earthquake. You can find me both high and low, usually out of control. I can be considered both good or bad, sometimes used for both happy or sad. What am I? Answer: Singing Pitch. — by Corey W v2.