This is band btw. Please help me i dont get these

Ablank is a type of chord that consists of three pitches on consecutive lines or spacesa. monophonyb. chordc. triadd. natural

Most flexible painting medium, used to create both thin, polished layers and thick, gestural brushstrokes

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