Hastily scheduled, this is another special preview installment of The Sixties, the forthcoming CNN documentary series by Tom Hanks’ production company. The first of these, back in November, was keyed to the golden anniversary of the assassination of John F. Kennedy. Now, two months later, comes a much happier 50-years-later program: a salute to the Feb. 9, 1964 appearance by The Beatles on The Ed Sullivan Show.