Note 35 — Chapter III

In connection with the statement that music has developed according to natural law, it is worth noting that the four-part chorus early became the standard for both vocal and instrumental groups for the simple reason that there exist two kinds of women's voices—soprano and alto, and two of men's voices—tenor and bass. Originally, the chief voice in the ecclesiastical chorus was the tenor (teneo), because the tenors sustained the melody. Below them were the basses (bassus, low); above the tenors came the altos (altus, high) and still higher the sopranos (sopra, above).