In 1939, audiences watched as a wide-eyed Judy GarlandAn American actress and singer who was born in 1922 and died in 1969. She achieved international stardom. stepped out of the black-and-white wreckage of her farmhouse, yapping dog in tow, and arrived in the Land of Oz, a dreamland of spectacular technicolour.

"Toto, I've a feeling we're not in Kansas anymore!" she said, marvelling at the winding pathways, road of yellow bricks, tall green vines and lotus flowers.

It is one of the most famous movie moments of all time. Wicked, a new Hollywood blockbuster spinoff of The Wizard of Oz, is expected to smash the box office worldwide this winter. The UK will see its cinema release today.

It is the first half of a planned two-part adaptation of the hit musical Wicked, penned by Stephen Schwartz.

In the run-up to its release, there have been Wicked cocktails, cosmetics and even Crocs. The stars, Cynthia Erivo as Elphaba and Ariana Grande as Glinda, had a cameo at the Summer Olympics.

But is there substance behind all the sequins? Alternately written as childhood fairy tale and adult parableA story told with a moral or spiritual purpose., it is rich with themes to appeal to people of all ages.

Sacred sisterhood. The central theme of Wicked is the relationship between glitzy Glinda, who will become Glinda the Good, and outsider Elphaba, who will become the Wicked Witch of the West. The girls become fast friends, but are torn apart by a shared love interest and differing values.

Vice and virtue. Elphaba, a misunderstood outcast with bright green skin, was written as the villain in the 1900 children's novel The Wonderful Wizard of Oz and its film adaptation. But Wicked suggests that she is merely misunderstood, with a different moral code from others.

Lasting legacy. The Wicked universe has a rich history extending back to L Frank Baum's 1900 novel The Wonderful Wizard of Oz. Wicked nods to this theme of legacy: whilst Elphaba strives to redefine her family's legacy, Glinda becomes preoccupied with the legacy that power can leave behind.

Power and repression. Abuse of power is a major theme in Wicked, as the Wizard seeks to subjugateForcefully bring under control. sentientAble to perceive or feel things. animals and uses his secret police to implement a system of totalitarianWhen a political system or leader requires complete subservience to the state. In a totalitarian system, people are not allowed to express their own opinions. repressionThe act of subsiding something by force. Repressive is usually used negatively, often to describe the activities of authoritarian states..

Blind bigotry. Elphaba faces relentless discriminationWhen people are treated unfairly due to characteristics such as gender, race and age. throughout her life. Her green skin marks her as different to others, and means they are less likely to take her seriously.

Does the movie have an important message?

Yes: There are many important themes in Wicked. From more light-hearted explorations of the value of female friendship, to serious debates about the nature of power and control, it is a feast for the intellectual mind.

No: Wicked has been marketed mostly to children, with themed dolls and children's clothes appearing on shelves. Its themes will not go beyond the bounds of a simple childhood fable built to show "right" and "wrong" without any nuanceWhen an issue has fine distinctions; is subtle..

Or... Do not allow yourself to be deceived that Wicked is a work of art. It is built to be unchallenging and uncritical. To attract the largest possible audiences, moviemakers have to be morally equivocalUncertain or ambiguous. It comes from the Latin words "aequus" (equal) and "vocare" (to call)., playing to both sides without making any serious points.

Judy Garland - An American actress and singer who was born in 1922 and died in 1969. She achieved international stardom.

Parable - A story told with a moral or spiritual purpose.

Subjugate - Forcefully bring under control.

Sentient - Able to perceive or feel things.

Totalitarian - When a political system or leader requires complete subservience to the state. In a totalitarian system, people are not allowed to express their own opinions.

Repression - The act of subsiding something by force. Repressive is usually used negatively, often to describe the activities of authoritarian states.

Discrimination - When people are treated unfairly due to characteristics such as gender, race and age.

Nuance - When an issue has fine distinctions; is subtle.

Equivocal - Uncertain or ambiguous. It comes from the Latin words "aequus" (equal) and "vocare" (to call).