What is this for and how does it work?

When the percussion section played the theme, the theme was less recognizable since most percussion instruments aren't tuned to a pitch the instrument sounds included drums and cymbals both a and b neither a nor b

In which quotes does the author use the word "chains" literally? in which quotes does she use the word figuratively?

In a paragraph of no less than 125 words, explain the single most important factor involved in advancing american classical music in the twentieth century.