If you were not aware that Thomas Balmes had, for his documentary Happiness from 2013, already visited a remote community of Bhutanese monks, you could be forgiven for taking the opening scene of Sing Me a Song as a spot of fakery. We see young Peyangki pondering the lack of technology in his village. “I want to live in a house and pay for the electricity,” he says with an impressive grasp of economic reality. We see men erecting pylons.

Then the film cuts straight to Peyangki, now a young adult, waking up to a familiar smartphone ringtone. It is the lower key, documentary equivalent to the match cut from spinning bone to orbiting space ship in 2001: A Space Odyssey (not a movie that otherwise much resembles Sing Me a Song).

Are we about to watch a film in which the monks lives are immeasurably improved by the arrival of handheld devices? Will their spiritual perceptions be enhanced or corrupted? Are these questions sufficiently rhetorical?

One among many striking shots finds the monks in Peyangki’s community praying vigorously as the camera pulls out to reveal each staring at a phone as other worshippers might scrutinise a prayer book or a sacred icon. Almost every shot from here on is partly illuminated by that small glowing rectangle. The hero is now part of a devotional cult that covers all continents and all strata of society.

We gradually piece together the familiar particularities of Peyangki’s case. He has, via a chat app, become remotely close (a common oxymoron these days) to Ugyen, a young woman living in the capital Thimphu. He eventually journeys to that city and discovers that – welcome to the internet, baby – she has not been telling him the whole truth. Ugyen has a daughter and she is planning to leave the city. There are the makings of a Victorian novel or an Apichatpong Weerasethakul movie in that scenario.

The unexpectedly soapy quality of the narrative helps drive the documentary forward, but what really sticks in the brain are the quasi-surreal depictions of a clash between ancient ritual and contemporary moral corruption. Some of these are a little too on-the-nose. The monks happen upon a collection of toy guns and – inadvertently echoing Powell and Pressburger’s Colonel Blimp with “Word War starts now!” – play aggressive combat games in the neighbouring fields. If there is an implied criticism here it is of a school of play that predates the Buddha’s birth. The sequence is, nonetheless, striking.

Elsewhere, Balmes appears to admit that the current technology does offer a degree of temporary transcendence. Peyangki and dozens of others, each wearing illuminated headphones, sit in a computer-game complex while an electronic drone builds up hypnotically on the soundtrack. One rarely sees such devotion in church these days.

For the most part, however, this feels like a tale of innocence corrupted. When the protagonist says “I’m too far from Buddha now” we wonder if that distance would have imposed itself in an era without the handheld devil. Quite possibly. The fleshy temptations of civilisation have been leading devotees astray for a millennium or two. But the difference now is that the novice need not leave his bedroom to connect with every imaginable debauchery.

Not everything in Balmes’s film speaks of pedant-approved documentary purity. The camera seems awfully close to some of the participants. The crew are present for disconcertingly intimate conversations. The metaphorical fly is not happy remaining on his figurative wall here.

This, nonetheless, remains a remarkable yarn that, in revisiting a subject after first encounters a decade earlier, kicks up unavoidable reminders of Michael Apted’s Seven Up! series. Watch it online. But try to avoid watching it on your telephone.

Available to stream