You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did the beatles became popular in the us?" whose answer is February 1964.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did the beatles become popular in the us
Useful Output:

Doc 1: The Beatles had unprecedented success in the USA when they touched down in 1964, beginning what some see as the British Invasion.
Doc 2: Their initial U.S. singles, released by Vee-Jay Records, were sent to blues, jazz and soul DJs, not to pop music stations. The Beatles didn't
Doc 3: Fifty years ago the Beatles conquered America, touching down in New York on February 7, 1964, and making their live U.S. debut two nights later
Doc 4: The Beatles were undoubtedly the biggest band of their era and, arguably, ever. Here follows a full Beatles timeline, from their humble
Doc 5: The wave of Beatles popularity had been surging and cresting in America through the latter part of 1963. The Beatles had created quite a stir in