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 interventions of the United States, the Soviet Union and China turned civil wars in Vietnam, Laos and Cambodia into proxy wars. This provides an answer to those who claim that the United States, by its intervention, mistakenly turned a pure civil war in Vietnam into part of the Cold War. The United States shared its belief that Indochina was a major theater in the global Cold War with the Soviet Union and China.