THINK Nick McCarthy and the next two words that many will think of are “Franz” and “Ferdinand”. For well over a decade McCarthy was Alex Kapranos’s right-hand man, a multi-instrumentalist integral in marshalling the hugely popular Glasgow-based band’s arch pop, a guitarist whose taut lines would surely snap in less capable hands.

And then, last summer, after touring FFS, Franz Ferdinand’s excellent collaboration with Sparks, he announced his departure from the band. It wasn’t a case of “musical differences” – “those differences are what we formed the band around in the first place,” McCarthy stated at the time, but to focus on his young family, production work at his London studio, Sausage, and to “write some completely different things for a bit”. Within days of that announcement a track titled Cracks In The Concrete by an artist simply called Manuela was made available on the website of Lost Map Records, the decidedly off-kilter label helmed by Johnny “Pictish Trail” Lynch.

With spidery guitar lines scurrying and jutting around whipsmart beats and the cool, dispassionate vocals of Manuela Gernedel – who is also McCarthy’s wife – Cracks In The Concrete may be the most “Franz” track on the forthcoming self-titled album. And that family connection should not indicate that Manuela is a vanity project for a man who’s content to have done his stint as a world-travelling, million-selling popstar and wants his wife “to have a shot”. That would be very wrong. The pair have been writing songs since they met in the late 1990s at youth club summer party in Bavaria, Germany, where they both grew up; they moved to Glasgow when Gernedel was offered a place at the School of Art to study painting and the pair, along with their friend Alexander Ragnew, have so far released two eccentric albums as going concern Box Codax.

What’s most immediately surprising about the record is how slinky, sultry and jazz it is. The track March Against It in particular, features a sax solo so jazz you need to peel yourself off the ceiling afterwards. Then again, before Kapranos cleverly bagged McCarthy after meeting at party, the latter was in the highly rated improv jazz band Scatter, and there were rumours that he had a background playing jazz in Germany. Perhaps few are aware that the band he played with were – and still are – cosmic rock legends Embryo, a collective routinely looked upon as one of the most eclectic and respected in German postwar popular music. Though a gifted and classically-trained musician, that experience must have blown the young McCarthy’s mind.

“Erm, yes, well I did get into jazz at some point,” he says. “I used to play in the amazing German krautrock band Embryo and they were heavily influenced by 1950s and 1960s jazz music. I even got to play with Billie Holiday’s pianist Mal Waldron. That was one of the best things that’s ever happened to me actually. So then I moved to Glasgow and started playing with Scatter and we played a few songs that I’d learned from Embryo. They’ll always be a massive influence on me.

“The saxophone piece on March Against It is written with some 1960s jazz marches from the Civil Rights movement in mind. It’s something for us hippies to march to in these crazy new times.”

Crazy is not a tone which features on the record; apart from a blissful dub retake of Invincible, a beautifully tender track Gernedel wrote about the pair’s children, this is an airy, summery, laidback record though never predictable and never without human complexity. Recorded with Django Django’s Jim Dixon, Mystery Jets’ William Reese, Veronic Falls’s Roxanne Clifford and Franz/E.Bias/AMOR drummer Paul Thomson (“four of the best musicians I’ve met,” says McCarthy, “a dream band”) and co-produced and mixed by Sebastian Kellig, every further listen reveals the record to be very much Gernedel’s.

Just as her vocal style is at once both cool and intimate, so her lyrics weave big themes such as impermanence and love around the minutiae of everyday life, no more sumptuously than on current single Supermarket where she “checks for bargains on the lower shelf” and sees you “melt in the heat, like cheese on rye”. It’s a unique record unlike anything else you’re likely to hear this year.

Manuela is released on March 31 via Lost Map