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.
Why did the United States become involved in the Vietnam War in East Asia? The U.S. become involved in the Vietnam War as a way to prevent a communism takeover of South Vietnam while training them to fight. What event proved to the United States that it would not win the war in Vietnam and what happened in this event? Tet Offensive. North Vietnam showed it could win the war because they attacked all of our bases and most major cities.