Imagine... Freddie Mercury: The Great Pretender, BBC One, review Twenty-one years have passed since Freddie Mercury, the flamboyant Queen frontman, died, just a day after publicly announcing he was HIV positive. A musician with a reputation for hedonism, the sudden and shocking nature of his death was an insight into the difficult personal life that Mercury concealed behind his on-stage persona. More than two decades later, shamefully little is known about the reclusive rock star who shaped the British music scene. Imagine... Freddie Mercury: The Great Pretender (BBC One), part of Alan Yentob's documentary series, was a frank attempt at uncovering the secrets of Mercury's private life. Focused on the years between 1985 - when Queen were at the height of their fame - and his death in 1991, it celebrated the singer's life outside the band, including his forays into the New York gay scene of the early Eighties and a raft of quirky solo projects. Rare interviews with Mercury and his late partner Jim Hutton featured alongside tributes from friends (Paul Gambaccini), admirers (Matt Lucas) and ex-bandmates Brian May and Roger Taylor. It was colourful, entertaining and full of black humour. We learnt that all the members of Queen were stuck in a lift when they found out Bohemian Rhapsody had reached No 1, that Mercury resented sharing a studio with Michael Jackson's pet llama, and that he "fought like a kid" with May, whom he once nearly punched. One of the highlights was a previously-unheard collaboration with Jackson (that "nearly made it on to Thriller") and behind-the-scenes footage from the 1988 Barcelona album, recorded with Spanish soprano Montserrat Caballé. This groundbreaking rock-opera was, director Rhys Thomas explained, one of Mercury's proudest achievements. Recorded in the immediate aftermath of his Aids diagnosis, it saw Mercury at his most raw and uninhibited - a fact powerfully conveyed in a series of emotional interviews with Caballé herself. With so much of Mercury's career already explored, and legions of Queen fans attending sell-out We Will Rock You performances in the West End (now in its 10th year), it is difficult to tread new ground. But Yentob's affectionate tribute captured Mercury in a new light. Cutaways of pulsating crowds chanting Queen lyrics alternated with poignant shots of Mercury, standing alone, cigarette dangling from his fingers. We saw him as a buck-toothed toddler growing up in Zanzibar; a long-haired teenager dressed in a fur coat, guitar slung round his shoulders; and finally a glitter-clad frontman, leaping across the stage with boundless charisma. There were insights into Mercury's tortuous relationships with others, including his hurt after the betrayal of his personal assistant Paul Prenter and his difficulty coming out to ex-girlfriend Mary Austin. "It's harder for other people to try and understand me as a normal person," said Mercury, in his last recorded interview. In one way, I think the more mishaps I have the better my songs are going to be. As well as Mercury the musician, it was a touching take on Mercury the man. A hurricane on-stage, he described himself as "quite boring" in real life. "Freddie was a shy boy who worried about his skin and his teeth," said May, "but he overcame everything to become a rock god." A rock god who loved ballet and opera. Who danced to Donna Summer in his living room. Who kept his Aids diagnosis a secret, attending radiation therapy at 5.30am so nobody would see him. Who was, in his own words, the greatest pretender of them all.