Yes, I am positive about this history. It's likely even on Wikipedia.
On another topic, the human voice is a unique ‘instrument’ and able to create a continuous range of sound with proper training. For four centuries, from the early 1400’s until Beethoven’s death, European children were taught to sing in an extraordinary manner known as bel canto (“beautiful song”).
That Renaissance practice was believed to develop creative powers of human perception (viz, expanded consciousness). But singing scales later were altered and bel canto became the lost art that it remains today.