"FUCK. WHY DID MENOMENA BREAK UP?" said one Twitter user earlier this year, evidently a latecomer to news of the band's internal fallout in January 2011.

The announcement of founder member Brent Knopf's departure, foreshadowed several months earlier by a series of spectacularly bleak interviews with the band, presented little surprise but sucked nonetheless: the Portland three-piece had, after all, been responsible for at least two of the most creative, interesting albums of the last decade, and any shift to their dynamic surely threatened it. “After a decade you’d think we would learn to fix our problems,” said co-member Danny Seim in 2010. “But maybe those problems are what make us tick.”

Theirs has always been a dichotomous sound, a restless dance between the exuberance of the arrangements and the darkness of the lyrical themes. Knopf's departure hasn't changed this: Moms still draws from the same poisoned well as 2010‘s Mines and 2007‘s Friend and Foe, its carnival sounds laced with conflict and dysfunction. “Heavy are the branches/Hanging from my fucked-up family tree” sings Justin Harris on 'Heavy Is As Heavy Does', a dark lament for an absent father set against a deceptive array of trumpet blasts and unhinged guitar, the piano lines just a touch too hummable for the subject matter that rides upon them.

Indeed it’s easy for a casual listener to overlook the album’s fractured heart, distracted by the glut of instruments vying for attention: the wayward percussion and the fairground synths, the peals of distortion and the textures of flute, the structural shifts and the tangential rhythms. Menomena make music not so much to dance to as to twitch a little erratically, lost and solipsistic in a surround of movement and colour that shifts too quickly to catch the fraying edges and the darkening hues: these blur into focus only later, once the melodies have taken root and started to decay.

But Moms is never bleak, nor ever anything less than captivating. Make no mistake - like all of Menomena’s work it takes some time, but as with all of Menomena’s work it’s worth it. There’s more imagination, energy and sheer musical nerve in these 50 minutes than in most other albums this year combined, from the trumpet squalls and layered melodies of 'Pique' to the slow build and involuntary singalong of 'Plumage', the tangled weave of 'Tantalus' to the broken, exhausted vocals on eight-minute closer 'One Horse'.

Yet for all its density the album is possibly strongest when the exuberance is pared back, the layers given space to stretch out a little and breathe. Album highlight 'Capsules' rests on a massive hip-hop drum, the vocals hazing out two minutes in beneath a playful embrace of bass and keys and pretty flutes and distended synths, joyful and unhurried.

They’ve never really sounded like anyone else, Menomena, although that’s no longer quite true: Knopf may have left the band but his Ramona Falls still echoes with their sound. There’s the same eclecticism of musical influences, the unconventional structures and the ceaseless experiment, the familiar tortured focus upon broken family, apt given the two bands’ history. There’s perhaps nothing here to rival Knopf’s 'Spore' from this year’s Prophet - that song’s damn near perfect - but as an album Moms is more coherent overall, richer and livelier and more, well, entertaining.

Of course, it’s heartbreaking too, but that’s Menomena’s strength: that they succeed in holding two near-contradictory positions together, the bright lights and the breakdown, the party and the tears, often in the same four minutes but never seeming mawkish, never settling for mere sentiment. It’s amazing, actually, that despite having been around for over a decade, through trauma and breakups and now their fifth record, Menomena still sound fresh and uncontrived and, well, endearingly innocent.