What is the worst thing you've ever eaten?

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.

Riddle me this: i am first in earth,second in heaven,appear two times in aweekyou can only see meonce in a year, althoughi'm in the middle of sea.what am i?

Which type of music most influenced the emergence of jazz in the postwar era?