The exact size, of course, depends on the playing time (in minutes and seconds), on how good the original compresses and the compression quality. 1 Mb a minute is a good approximation, in practice. I wouldn't trust 2 Gb to hold 1000 average downloaded songs. Just go for 4.
The causes of the Vietnam War were derived from the symptoms, components and consequences of the Cold War. The causes of the Vietnam War revolve around the simple belief held by America that communism was threatening to expand all over south-east Asia.
The United States began to give extensive aid to the French in 1950, when, after the outbreak of the Korean War and the end of the Chinese civil war, American leaders believed that Communism was spreading throughout Asia. Thus, U.S. involvement in Vietnam was a direct result of the Cold War.