"Don't Look Back." Paramount. $39.95. More than simply the most probing documentary ever on a pop star, D. A. Pennebaker's look at Bob Dylan's celebrated 1965 solo tour of England also stands as a fascinating examination of a major creative force dealing with fame. Where "A Hard Day's Night" entertained us by re-creating the lightness of the public Beatles experience, Pennebaker slips us into a more private and intriguing scene as he focuses on the tension that grows out of the arrogance of celebrityhood and the struggle for artistic independence and growth. A classic.