The Reflektors - London Roundhouse, 11 Nov

Arcade Fire have been accused in some quarters of lacking levity, which maybe goes some way towards explaining the promotional bumph for their fourth record – the pseudonyms, the masks, the bonkers long-form video, and so on.

Clearly Reflekor is an attempt to push the boat out musically too, the hiring of James Murphy heralding extended track lengths and an emphasis on beats more than riffs. Win Butler has also talked a lot about how visiting Haiti inspired many of the songs, and how the locals respond to music in a more primal way rather than viewing everything through the Western prism of “rock”. Such comments are on a hiding to nothing really, as a multi-award winning, adored band will never be able to escape their pop-cultural baggage. The best they can do is to throw out some new shapes, mix things up a bit and hope not to lose the qualities that got them here in the first place.

It must be said that all this makes far more sense live than on MP3, especially since the Roundhouse now represents a tiny environment by their standards. And being able to play for their most hardcore followers, happy to splash out 40+ quid to watch a shorter-than-normal set with no support (unless you count the mariachi band in the foyer) in wacky/ironic attire, certainly helps.

Generally the new material is a rough hybrid of Sandinista!-esque scope and LDC Soundsystem sonics that doesn’t quite scale the heights of either. The overriding feeling with the likes of Joan of Arc and We Exist is of compact rock songs with decent hooks being stretched like elastic bands in an attempt to fit into dance-shaped moulds. The title track's groove gathers enough momentum to get away with it, but others such as Afterlife run out of steam, the buzz from Butler’s early rabble-rousing intensity dissipating long before the end.

The relatively out-there stuff is more successful. Here Comes the Night Time starts frenetically then careens into a lush midtempo calypso, and looks set to become a live highlight. Flashbulb Eyes is a good stab at 21^st-century dub which perversely clocks in at under three minutes, suggesting that they still have an ear for brevity but have mostly chosen to ignore it in the hope of Making A Statement. It’s great that they’re pushing their boundaries with Reflektor, but it’s doesn’t represent rock’s great leap forward either.

A few older songs are included in the set, reminding us of what they’re capable of at their peak. The energy rush of Neighbourhood #3 (Power Out) is dropped early on, with a rare airing of Crown of Love plus Sprawl II and Haiti to close proceedings. Regine Chassagne twinkles and shimmies as beguilingly as ever in the latter two, but an epic singalong closer in the vein of No Cars Go or Wake Up is conspicuous by its absence.

Such negativity must of course be put into context – Arcade Fire are comfortably one of the 21^st century’s great bands and if their new adventures don’t measure up to their initial highs then they’re only following the modern template of arriving with a bang and then never quite sustaining that quality. Their energy – always positive, always channelled towards the audience – and, yes, earnestness always make for exciting live performances. The occasional masks, party theme and concluding tickertape shower draw comparisons to the Flaming Lips, but you sense they are only semi-comfortable with such frivolities. For AF, music is a serious business, and one which doesn’t show any signs of slowing down yet.