Every so often a song will spring up that demands the listener adjusts their antennae. ‘Eikon’, the opening track on Love’s Spring, takes fewer than five seconds to make an impact, and five minutes to retune your brain. In the same way as a disruptive innovation redefines the marketplace, so this insistent record will make unusual demands on the way modern albums are received. These songs were not made for commuter soundtracks or jogging at the gym. You have been warned.

The Two Wings collective first evolved as a side-project partnership between artist and singer Hanna Tuulikki and former Trembling Bell Ben Reynolds; later swelling to a quintet. Leaving behind an eclectic array of past projects and old collaborators (the band do wonders for the Six Degrees of Separation theory), this particular coming together is a union forged in electric folk and brought to life by Tuulikki’s extraordinary voice.

Pushing beyond the stark and ardent tones achieved by Maddy Prior, say, or contemporary Lavinia Blackwall, Tuulikki’s visceral lead vocals create invigoratingly irregular effects. On ‘Eikon’ her voice transcends crisp and curled, squealed and squally, enticing and menacing. Its forbidden-fruit sweetness is deadly, not cutesy; alluring siren with a hint of emergency services siren thrown in. Underneath, the fluctuating tune tends improbably towards country rock in places, which – even less predictably – fits the bill rather well.

An expansive title track finds the five-piece flirting with the free-form frontier between folk tales and prog rock atmospherics – somewhere after King Crimson and Fairport Convention, anyway – and is the album’s zenith. These frenzied highs are tempered by milder moments, including second song ‘Feet’, a coyly adorable duet with Reynolds. The potential delight of peeling layers away is never fully realised, however. Even the solicitude of ‘Feet’ and the pain of ‘It Hurt Me’, comparatively pared down, are unrestrainedly embossed. ‘Valley’, perhaps unwisely, approaches hoedown territory in its final third (the country ploy is harder to pull off a second time) but Two Wings’ proclivity is still towards the soupy and stout. ‘Altars and Thrones’ is a heavy roller, sunless lyrics hanging on a weary tune.

Love’s Spring‘s strongest aspect is its catalogue of surprises – the euphoric choruses of ‘Just Like’, Hanna Tuulikki’s radical impact on ‘Eikon’ and her accomplice Lucy Duncombe’s subtle, shadowy subordinate vocals, often easier to miss than to catch. Over-long closing song ‘Forbidden Sublime’ suffers from the lack of Duncombe’s muted contrast. Tuulikki’s luminescent vocal alone is like writing with a highlighter pen.

There can be a certain immutability about Medieval-styled electric folk rock, historical at source, inscribed by history’s dried inks. Love’s Spring retains this sense of permanence but it also undulates, unsettling and uncanny, protean and perpetual too. It’s demanding, yes – but there are plenty of reasons to love this lavish album. Whether you do, ultimately, depends on your regard for its lead vocalist.