Answer
Stringed instruments are less efficient than wind instruments at setting air into motion, so there must be more of the former type to provide a balanced sound.
Work Step by Step
This is discussed on page 396.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.