Gruff Rhys has turned into an alternative national treasure, something which was not on the cards for the Super Furry Animals frontman back in the days of techno tanks and Hangin’ With Howard Marks. This quirky wee spoken word and music show relocates three decades of cosmic weirdness for a Radio 4 crowd. It’s part biography, part pop-psychology, with rich, intimate music in between. In fact, it’s very similar in spirit to Martin Creed’s Words and Music show from last year’s Edinburgh International Festival.

Rhys starts by introducing us to his early band Ffa Coffi Pawb (“fuck off, everybody” in the right combination of Welsh and English) using pictures and a couple of songs from the days when Bangor Normal College was their regular venue/home. There’s some jesting here – the Beatles learnt of Brian Epstein’s death while staying at the college, and Rhys laughs at how he used to sleep in the same phone booth – but what comes through strongest is the radical difference between this and canonical British rock culture. Not for Rhys tales of hanging out in Camden, or the Madchester scene of folklore. Late 80s provincial Wales was brewing up its own distinctive culture in almost splendid isolation, in a way you’d like to think still might occasionally happen somewhere, but which greater connectivity may have put paid to.

From here it departs from straight chronological biography. Much of tonight is devoted to Rhys’ struggles with chronic shyness and the methods he employed to overcome it. The most emblematic of these are the placards audiences at SFA gigs will be familiar with – “Applaud!”, “Louder!”, “Ape-Shit!” There’s several anecdotes related to these, and liberal use of them to get us started too.

This creative use of social terror will resonate with many, but as when that other national treasure Stephen Fry first opened up about mental illness, or any number of tears-of-a-clown stories, it’s also hard to square with Rhys the performer. His ultra-soft-spokenness is the only outward sign of reserve; his gigs are always full-on and in his own quiet way, tonight’s show is very assured, even the comic moments, which he can’t be all that practised at.

He juggles all the tech in a casually confident way too. The songs are gadget-heavy, with ticking metronomes, birdsong samples played straight off vinyl, vocal loops and other fx. It’s not showy. He’s not blinding us with science. It’s an insight into the natural, instinctive curiosity which has helped him create such luscious music. The setlist is mainly drawn from his solo career, including If We Were Words We Would Rhyme and recent single Frontier Man.

There are some diversions into psychology – the difference between a physical group and a psychological group in relation to gigs, and how people in crowds can be manipulated. To be honest, it’s a little late in a Pleasance Courtyard evening to be wrapping your brain around this sort of angle, especially in between mellower stuff.

One of the best of his anecdotes is the time Damon Albarn invited him to play an Africa Express gig with Paul McCartney. Ordinarily, that might be name-dropping, but Rhys is a humble man, genuinely thankful to be playing a gig with one of his heroes, and sets up a visual joke using some of the snaps from the gig. No airs and graces here.

The empty seats at the back of Pleasance Beyond testify to the limit of Rhys’ fanbase. He’s a treasure only within certain circles and there isn’t a lot for the uninitiated to grab a hold of. But to the rest of us, it’s becoming clear, if it weren’t already, just how singular and precious a talent Rhys is.