Last year the closing gala of The Times BFI London Film Festival was the launchpad for a film that became a global phenomenon. Slumdog Millionaire wowed the festival audience and the Oscar voters alike; its success at the box office matched its critical reception. It’s a tough act to follow. But while Nowhere Boy, the artist Sam Taylor-Wood’s engaging portrait of John Lennon’s formative years, will struggle to match Slumdog’s formidable financial achievements, the film’s crowd-pleasing credentials are beyond question.

We meet Lennon (played by Aaron Johnson) as a charismatic but complicated 15-year-old in 1950s Liverpool. Brought up by his brittle Aunt Mimi (Kristin Scott Thomas), John is plagued by half-formed memories and nagging family secrets that might hold the key to who he really is.

After the death of his beloved Uncle, John is reunited with his long-lost mother, Julia (Anne-Marie Duff). She is joyful, unpredictable: a fizzing firecracker of a woman who is as dangerous and damaged as she is fascinating. It is Julia who introduces her son to rock’n’roll, and — scandalously for a boy hitherto raised according to his aunt’s buttoned-up propriety — it is Julia who equates this new music with sex.

But for all her uninhibited, errant curls and profligate kisses, Julia’s effusive affection causes John to sour towards her as he starts to question where she has been all his life.

In bringing the young Lennon to life, Taylor-Wood has eschewed the more adventurous approach favoured by fellow artists turned film-makers, such as Steve McQueen (Hunger) and Julian Schnabel (The Diving Bell and the Butterfly). This is a solid, somewhat conventional biopic that showcases a skill for storytelling but no visual pyrotechnics or formal experimentation. Taylor-Wood has concentrated instead on getting the film’s foundations and the cinematic building blocks absolutely right. The script, written by Matt Greenhalgh, is well crafted. The teenage Lennon’s voice is authentically abrasive. He’s still learning the power of his sardonic wit — his gibes embed themselves like shrapnel in their targets.

The director of photography, Seamus McGarvey, also does sterling work here, as does the production designer, Alice Normington. The use of colour is particularly evocative. Mimi exists in shades of disapproving, airless beige; Julia favours a chaotic racket of reds and oranges. But Taylor-Wood’s trump card is her choice of, and work with, the film’s cast. Her three key actors are first-rate. Scott Thomas gives a beautifully nuanced performance that gradually reveals an extraordinary, fiercely protective woman beneath the crisp, cold veneer.

Duff is magnetic, impulsive but unravelling from the inside. And Johnson, in the difficult position of playing someone whom everyone feels they know a little, triumphs.

He conveys Lennon’s obnoxious swagger and confrontational wit, but also shows us every mercurial doubt and flickering insecurity, every spark of directionless anger. A star is born.

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