Glass Animals have been making plenty of fair-minded people sit up and take notice recently. Invited to play here by Meltdown’s curator James Lavelle (UNKLE), other champions have included St. Vincent, Radiohead and, perhaps most significantly, Paul Epworth, the man behind Adele and Florence Welch, who wasted no time in signing them up to his Wolf Tone label. As the apposite moniker suggests, their music is a delicate curiosity; there’s fragility on show, but there’s something tangibly bestial beneath the glassy surface. It’s like a snarl frozen in time. Tonight, a capacity crowd is here to see how the darkly subtle sound of their record works in the flesh.

Opening with a rousing rendition of “Psylla”, they play like they’ve just been released from caged environs and back out into the wild. It’s bubbling with energy. There are certainly reference points to be found here. For all the easy comparisons to alt-J, (most noticeable on the slow jam “Toes”, but there’s certainly a similarity in the RnB-flavoured breaks that permeate the set), Wild Beasts might be closer bedfellows, with all their libidinous sensuality that is on display here tonight. They’re yet to write a song that’s explicitly sexual, but hey, they’re still young. There’s always time.

There are moments when they channel the anti-funk of latter-day Radiohead, particularly the swirling outro to “Walla Walla”, and they certainly have kindred spirits in the electro-folk circus sounds of CocoRoise (“Black Mambo”, “Cocoa Hooves”) or dance-punk weirdos Late Of The Pier without the more outlandish electro-histrionics (“Wyrd”, or standout moment “Pools”). But the wide range of these influences is testament to the broad pallet that is on show here tonight. Drawing in sounds from pop’s sonic fringes, they have collected and curated their own bizarre installation, like Victorian curiosity peddlers or taxidermists, led by a whispering and understated ringmaster. And the stage-set only adds to this tension between the organic and the contrived. Yes, they’ve brought the contents of a botanical garden greenhouse with them, but they’ve also brought LED strips and worker lights. It’s like a film-set. It is of the wild, rather than in the wild. “Welcome to my zoo,” Dave Bayley sings on “Toes”.

What makes the Oxford four-piece’s debut, ZABA, so alluring is the breadth of minute details that build up to make a glorious whole, like an entire sonic ecosystem is alive and working for greater good of the record. The delicate production is a thing of beauty. Tonight, perhaps inevitably, some of those moments are sacrificed, but we’re provided with something quite special in their stead – a remarkable display of controlled and focused energy. They, and Bayley in particular, are a group always on the verge of cutting loose, but always just about finding the restraint to rein it in.

The same, sadly, cannot be said for the structural stability of the Royal Festival Hall’s Production Arch, the concrete box that provides this evening’s venue. As the set draws to a close, something dislodges and comes crashing down, mercifully avoiding anyone on its descent, but denying us the chance to hear any more. Bayley returns to the stage to explain and apologise, and the evening ends bathetically as the audience shuffles out. It could be that the perhaps overly dominant bass lines have shaken the foundations of this place, but its cruel on the band, who are in the process of building up to a grand finale, almost literally bringing the house down. They slope back into the trees and disappear from view; the travelling zoo rolls on, with dates in the UK, Europe and the US to come. We’ll be awaiting their return.