This subtle portrait of a reclusive indie musician seems to have generated one of London Film Festival’s warmest responses, with extra screenings needed for all the fans of Lawrence, the Birmingham-born progenitor of 80s and 90s bands Felt and Denim. Lawrence’s story is not a happy one: Felt’s ethereal guitar pop was arguably superior to, say, The Smiths, yet failed to rise above cult status; with Denim, Lawrence nailed 1990s indie’s obsession with nostalgia early in the decade, with a skewed wit and obsessive rigour that was probably a bit too much for Oasis and Blur fans. Mental health and drug problems have dogged his current band, Go-Kart Mozart, whose perverse synth-rock songs are exercises in self-sabotage lit by some occasionally inspired tunes and arrangements. Rather than construct a biopic focusing on his more palatable past, director Paul Kelly lets the present-day Lawrence steer the film, and it’s the better for it, albeit searingly moving and uncomfortable in places. We see Go-Kart Mozart stumble through rehearsals, recordings and some live shows, while Lawrence is interviewed by journalists (who seem in the main to still be holding a torch for Felt), sifts through archives of personal ephemera and moves into a new council flat on the edges of the City of London after being evicted from his previous home. The capital’s loneliness, its sharp, cold angles, are soulfully evoked by the filmmaker who also helped create St Etienne’s paean to London, Finisterre (2005).

Kelly’s a friend of the singer, and you suspect some of Lawrence’s more unpleasant, paranoid traits have been softened in the edit - although not that much; there’s a scene in which a new Go-Kart song seemingly about a fear of vaginas gets an airing. What he draws from Lawrence most valuably is his sharp critical intelligence and instinctive feel for pop music’s power and history - things that seem unextinguished by failure or addiction or age. Listening to Lawrence talk about music, the secret magic life of it, is a pleasure, however spectral and neglected he looks now: if things had worked out a little differently, if Go-Kart’s ‘We’re Selfish and Lazy and Greedy’ had taken off like ‘Common People’, perhaps he, like Jarvis Cocker - another almost-failure from the 80s who triumphed in the following decade - would be signing Faber deals and headlining stadia while pontificating about rare records on the radio. It’s this plucky eccentric almost-a-contender status that I think some of my fellow viewers of Lawrence of Belgravia seek to confer on him, but while it’s well-meaning, it implies a slightly sour triumph; Lawrence quite obviously would have liked to have been much more of a real star before becoming the outsider-ish ex-star he now appears to be.

Musicians from the 90s, thought to be retired, seem to appear in the media at almost weekly intervals these days with news of a tour and a hint of some precious ‘new material’, while BBC4 documentaries on Creation Records and films like the recent account of Oxford’s alternative music scene, Anyone Can Play Guitar, recount indie’s various ‘golden ages’. Lawrence of Belgravia is both part of this trend, and a disruption of it, because his presence and participation stop us from celebrating this recent past too complacently. He is something of a ghost at the nostalgia feast; a ghost with a comedy song about Rwandan landmines and Um Bongo. The light in which we’ve cast ‘indie’ and ‘the 90s’ fades into an agoraphobic sickliness; not everyone got out OK.

It is to Kelly’s credit that, despite the sadness at its heart, his film is so sincere, warm and affectionate. I loved it, but it left me chilled to the bone, writing 2000-word blog posts into the small hours, coshed with memories and having a good cry to Denim’s ‘I’m against the Eighties’. It was quite a trip, so I would advise any 30-something music nerds with similarly delicate dispositions to approach this film with caution.

Frances Morgan