I was surprised – nay, shocked – when recently I mentioned to some friends in their early twenties that I was going to see the biopic Judy, about the unmatchable Judy Garland. They had no idea who she was and only made any connection when I mentioned The Wizard of Oz.

As the greatest female pop singer of all time, Garland deserves to live on in our collective cultural heritage, so it’s good that Judy may at least let a new generation know there was once such a star. Yet in many ways this well-intended homage fails to do her justice.

It concentrates on a short period when, as an apparent has-been, penniless and addicted to drugs, she undertook a series of engagements at a London night club called The Talk of the Town. Even in her flawed state, though, she was able to score a mammoth hit with audiences.

Flashbacks to her life as a young star claim that her addiction began when the MGM studio gave her uppers and downers and diet pills in what can only be termed an abusive relationship, though in fact the regimen had been started by her mother, a quintessential “stage mother.”

We see something of her five marriages, her struggle to keep her family of three children (one of whom is Liza Minnelli) close to her, the artistic and economic mismanagement she suffered through her poor choice of staff, and, on a more positive note, her quick wit, sense of humour, and love of performing.

Renée Zellweger deserves credit for taking on the impossible challenge of playing Garland, and she may be widely recognized at awards time. Zellweger does a creditable job of conveying Garland’s physicality when delivering a song. She even sings the songs herself – and impressively at that, which will not surprise anyone who recalls her stellar work in Chicago, one of the greatest musical films ever.

Distractingly, Zellweger engages in constant twitching, which, to judge from interviews she has made in connection with the film, is part of her own persona rather than that of the addicted Garland.

Zellweger’s impression falls far short of the original, but who can blame her for that? Garland was and remains unique.

In other respects, the film also falls short. Over its two-hour running time, its reasonably fair portrayal of the pitiful reality of Garland’s last years does get repetitive. Even if it were going to concentrate on just this limited time, its purpose could have been better fulfilled. Period and place are hardly indicated. The critical appraisal of Garland’s performance is not shown, nor her place in the history of pop music. A brief scene of her chance encounter with two gay fans and a few vague nods to the reception she received in the theatre and at the stage door hardly convey the positive and affectionate response she engendered. Her incredible filmography, her legendary television appearances, her triumphant Carnegie Hall concert – these are barely touched on.

What Judy offers is, rather than a fully realized portrait, a provocative and moving sketch, which incidentally raises many disturbing moral questions about how the entertainment industry operates. What is presented is arresting enough, but one still regrets more was not done to show her greatness and tragic life.