Robert Lepage’s new nine-act epic Lipsynch featuring nine actors covers continents and inter-locking life stories with an ease, charm and brilliance that is totally beguiling, but the whole nine-hour-event – well under seven hours of theatre, with copious intervals – is an exercise in theatrical sleight-of-hand that exploits the medium in a way both exemplary and unprecedented.

The title correctly implies that the main theme is the dubbing of sound on a silent screen – or, indeed, a silent scream – and you could look at Lipsynch as a sophisticated update on the movie Singin’ in the Rain, where the coming of the talkies in cinema is the subject of comedy and delight.

But Lepage also embraces newer technologies of the dubbing studio along with stories of speech therapy, the voice-over culture in advertising and international cinema, the transcendent quality of music and the business of simply finding your own voice. The production itself, sets operated by an army of black-clad stage-hands, is an amazing physical and logistical achievement which defines the voice and timbre of the narrative.

We start in the sky. An illegal immigrant from Nicaragua dies on a flight from Montreal to Frankfurt; her baby is charitably adopted by an opera singer (Rebecca Blankenship), who becomes embroiled with a border guard in Frankfurt. The child, Jeremy (Rick Miller), grows up to make a film about his own story, a fantastically funny and ingenious fourth act which turns into something dreamt up by Truffaut and Almodovar.

En route, as it were – and watch out for the underground scene on the Piccadilly line - Jeremy graduates from Schumann to heavy rock. And as Thomas (Hans Piesbergen), the part-time border guard, develops his career as a neurologist, so the story pans out to include his treatment of a jazz singer (Frederike Bedard) with a brain tumour; that singer’s mentally ill sister’s solace in literature in a Quebec bookshop; and a murder mystery after a radio newsreader disowns his sex worker sister (Sarah Kemp).

It all loops round to a brutal revelation of the Nicaraguan mother’s fate in the sex slave industry, the subject of another documentary drama that leads to a final pieta of reconciliation and transfiguration. The staging is breathtaking: one minute, we can see the polyphonic laying down of musical lines on a big screen as it is performed; the next, the farcical despatch of a still-farting corpse in an over-occupied crematorium.

Finally, there is the beautiful, ironic metaphor of a stage performance giving concrete imagery to the babble of sound (we hear four languages, there are sur-titles throughout) and the manufacture of artificial substitutes in the search for explanation and perfection. There are two more complete cycles next weekend, and a performance spread over three evenings this week.

- Michael Coveney