It's now as ubiquitous an American pop-cultural icon as McDonald's, making judging the movie purely on its own merits an almost impossible task. Judy Garland's tragic later life, for example, makes her naïve and utterly beguiling Dorothy seem all the more poignant in retrospect. But this at least is clear: much of this movie's success depends on the winning appeal of Garland's "Everygirl" figure, who creates the vital identification and empathy necessary to carry the audience with her into the land of Oz. We always care deeply about Dorothy, her quest for home and the strength of her friendship with her companions. Garland's assured dancing and singing routines with her ideally cast Broadway comedy co-stars Ray Bolger, Bert Lahr and Jack Haley are still endlessly delightful, of course, and the songs and score (by Arlen, Harburg and Stothart) are as good as anything in the Hollywood musical canon. It is Garland's deeply felt rendition of "Over the Rainbow" that is both the film's emotional core and the reason why adults as much as children the world over still respond so strongly to this movie. So long as people long for home and the love of their friends and family, the nostalgic appeal of Oz will never fade.

On the DVD: another splendid digital restoration from the MGM vaults keeps this wonderful classic as vivid and alive as it was back in 1939, if not more so. The 1.33:1 picture is clear and defined, bursting with the vibrant colours of Oz (you can even see the wires holding up the Lion's tail). Even more remarkably, because the original microphone tapes have been preserved the soundtrack has been remastered in 5.1 stereo, thereby accentuating the lush tones of the MGM orchestra and Garland's famous singing.

The disc is also chock full of extras, including outtakes, audio sequences, composer Harold Arlen's backstage movies, extracts from earlier silent Oz films, clips from the Academy Awards and interviews with the stars among many other fascinating nuggets. The new 50-minute documentary hosted by Angela Lansbury, and irritatingly narrated in the present tense, is oddly the weakest part, with too little hard information and too much padding about how everyone loves the movie. The only gripe is Warners' trademark cardboard slipcase, which is awkward and easily damaged. But this is still an essential disc for the young at heart everywhere. --Mark Walker