 Complete the following phrase:  Released in May 1967, Sgt. Peppers Lonely Hearts Club Band is described by Doggett as the biggest pop happening to take place between the Beatles debut on American television in February 1964 and Lennons murder in December 1980. The album was a major critical and commercial success; through the level of attention it received from the rock press and more culturally elite publications, Sgt. Pepper achieved full cultural legitimisation for pop music and recognition for the medium as a genuine art form. Its win in the Album of the Year category at the 