Back in 2016, Young Fathers' brief collaboration and support tour with Massive Attack felt like a passing of the baton as much as an esteemed older act championing their younger peers. Occasionally – and incorrectly – pigeonholed in the same genre as the hip-hop clubs of Edinburgh where they first met, Young Fathers transcend easy definition in much the same way as Massive Attack continue to. Their sound is an algorithmic playlist, as random but subtly designed as any you might be served online, blending rock, rap, soul, R&B, trip-hop and industrial.

There's no-one like them, particularly in Scotland, and that's one reason they should be enthusiastically celebrated. The third album – arriving four years after they picked up a Mercury Prize and a Scottish Album of the Year Award – is the one they've been wanting to make since they were teenagers, says bandmember Graham 'G' Hastings, although it still manages to sound urgently, almost confrontationally, of its time.

'Here's the thing about progression / I didn't work this damn hard to stay where I belong,' growls the verse of 'Turn', a testament to the value of hard work and no expectation of help from anyone to get where you want to be. It's an anthem for those who are striving, but there's a surging undercurrent to be found here, one that sticks up for the underdog. Young Fathers are working class and racially mixed, and in the heavily loaded line 'don't you turn my brown eyes blue / I'm not like you', there's a powerful implied refusal to sell out their identity for success or easy acceptance.

There are some gorgeous, sumptuous beats on this record, but almost nothing which can be described as upbeat. Instead, the confident, soulful voices of Kayus Bankole and Ally Massaquoi lend it heart. As the title is supposed to imply, it's a bittersweet listen, and their vocals leaven the pneumatic, gospel-infused groove of 'Border Girl' and the scything rhythm of 'Holy Ghost', both of which allude to the refugee experience, and toughen the edge of jittery industrial sex groove 'Wire' ('oh ya fucker / I can dance… I can love… I can push') and neon-streaked amphetamine rush 'Wow'.

This is music which accomplishes that great storytelling trick of leaving you wanting more by withholding as much as it can, from the evocative obscurity of the lyricism to the suggestive musical motifs the trio add here and there – the metallic sawing noise in 'See How' that recalls Arthur Russell's 'This is How We Walk on the Moon', for example, or the recurring piano line which floats in and out of 'Fee Fi'.

It's a record that brilliantly touches upon love, sex, race, class, religion, aspiration, poverty, fame and more besides, but buries all of this beneath a bed of gorgeous music to be discovered by the committed listener. It's the definitive sound of 2018 – and in another universe, Young Fathers might actually receive all the acclaim they deserve.

Cocoa Sugar is out on Fri 9 Mar, on Ninja Tune