The buzz surrounding this one-off performance by the enigmatic, famously reclusive, modern-day renaissance man, Keaton Henson, is tangible. His only other live performance of 2014 came at the Antigel Festival in Geneva back in February, so tickets for this event, part of James Lavelle's 'Meltdown' at the Southbank Centre, have quickly been snapped up.

For all the talk of Henson's crippling fear of live performance, the evidence that he appears to be conquering his stage-fright is promising. Despite creeping from the wings in near-darkness and the occasional pregnant silence as he moves between the grand piano and guitar, he introduces his songs with a softly-spoken charm and strikes up an easy rapport with his audience. Spontaneous laughter en masse isn't something we'd expected to hear that evening.

He tells the crowd how 'Lying To You' was written while killing time in a bleak Los Angeles hotel room, and that it was especially significant for him to play the Queen Elizabeth Hall as he'd once seen his hero, Randy Newman, performing there on the very same stage. Invaluable details for his ardent fans who are certainly vocal enough between songs to let Keaton know just how affecting people find his music.

Like so many expansive artists, Keaton Henson seems to enjoy collaboration, Birthdays featuring guest musicians on several tracks. His new classical album Romantic Works, from which he plays several songs, was written closely with Ren Ford, cellist from The Josella String Quartet who accompanies him for most of the show. The stage itself is designed by artists Clarke & Reilly; a floor arrangement made up from over 3,000 antique car wing mirrors framed by rustic wooden beams, reflecting light elegantly around the venue.

Altogether, this feels like a special event. The venue's perfect and the music gorgeously rendered live; delicate and sincere, hitting all the same impassioned lows (and occasional highs) you can draw from the records. The set is over within the hour but never misses a beat, including favourites and rarities from his entire back-catalogue, managing to be both intimate yet grand. Some may find him self-involved or maudlin, but that would be missing the point. If we all felt love, loss, guilt and fear as acutely as Keaton Henson, and were all able to express it as beautifully, he wouldn't be quite so special.

Part of me thinks I should go really, really easy on Keaton Henson's debut album Dear.... Recorded alone in his bedroom and never performed live owing to Henson’s crippling anxiety, I'm reticent to turn the screws on a release which presumably marks a huge leap of courage for him, being brave enough to submit these songs for public approval. But combining the brink-of-tears vocal work of people like Damien Rice and Perfume Genius with the rustic fingerpicking of last year's excellent Josh T Pearson record (saturated with all the dourness and heartache implied by these comparisons) requires an artist to walk a very, very fine line, the slightest hint of artifice or unwarranted melodrama bringing the house of cards down quite dramatically. And sadly, there's a slightly try-hard streak running through Henson's affectations which ultimately make these ten songs eye-rolling rather than eye-watering.

One of the biggest nails in the coffin to Dear... is the sourness which laces most of these tracks. Whilst the slightly peppy midpoint 'Sarah Minor' hits a pleasant better-to-have-loved-and-lost tone with a breezy sing-along melody, most songs on offer are dripping with a barely concealed narcissistic rage that this woman had the nerve to leave him/reject his advances. Hands down low-point 'Not That You'd Notice' brings in a group of crooning voices to bolster Henson's passive-aggressive revenge fantasies (“I won't move till you love me / I won't dance till you hold me / And it won't be long / Till you know my song... I think we'll be even then don't you agree?”) - an intensely grating dirge, being impossible not to picture the backing vocalists swaying together to the music, holding fucking candles, bursting into hysterical tears and falling into each other's arms just as soon as the song's over.

These songs play like a catalogue of recent singer-songwriter break-up-song clichés, such as the focus on small, mundane details of a relationship in order to convey a nu-masculine sensitivity with all the proficiency of a Nick Hornby novel – lines like “I miss your small hands in the palm of mine / And the fact they're good at making / Miss you sitting up incessantly / And the fact you're always waking in the night” being so twee that they make you want to eat your own teeth. But the truly irredeemable undercutting of this album is his apparent petulance in the face of heartbreak, coming across as being absolutely convinced that he's been so desperately wronged – can't she see?! It's spite re-branded as sensitivity owing purely to the fragile arrangements.

As I've said, plenty of people are going to love this (plenty already do), because this sort of life-on-the-line album lives or dies by its ability to sell itself to you convincingly – something it's clearly achieving with a huge audience of listeners. For me, however, without the counterbalancing self-awareness and occasional flashes of redemption displayed by similarly downtrodden artists like the already-mentioned Perfume Genius and Josh T. Pearson, even the terrifically gorgeous melodies of many of these songs (such as widely lauded single 'You Don't Know How Lucky You Are' and the genuinely lovely 'Flesh and Bone') wither in the face of Heaton's overbearing melodrama – an extended exploration of having been shit on from a great height so relentless that it becomes hollow and unconvincing. If you have any taste for this sort of tortured (or, should I say torturous?) acoustica, then there's plenty of effective connection between Heaton's warbling vocal and aching guitar to please you – but sadly his overwrought attempts to be honest and display sensitivity ultimately brand Dear... as an unwelcome exercise in self indulgent posturing, desperate for undeserved sympathy.