‘Walhaz’ is a very old word, if it was a word at all, from the hypothetical Proto-Germanic language, meaning ‘foreigner’. The words ‘Wales’ and ‘Welsh’ most likely derive from it. The word itself can also mean ‘stranger’. Well har-de-har and badum-tish, because they don’t come much stranger than Gwenno. That’s a truly terrible attempt at an opening paragraph, but an artist who performs mostly in Cornish, with some Welsh thrown in, is always going to sound odd at the very least to ears not attuned to the Brittonic languages.

Giving off an ethereal air, like a sort of good witch out gathering mushrooms on a dew-soaked forest morning, Gwenno’s stage presence is pretty magnetic. Her three-piece band trash through ‘Sisial y Mór’ from 2014’s predominantly-Welsh Y Dydd Olaf while she tambourine dances in front of them. There’s a hint of both Bjork and Kate Bush in the ahh, ahhs of ‘Hi a Skoellyas Liv a Dhagrow’ and when she introduces ‘Tir Ha Mor’ with “my name is Gwenno, these are my dreams” one can only nod in agreement for this is music for which the adjective dreamlike was invented. ‘Chwyldro’ is accompanied by some sort of electric lyre/harp hybrid. It vaguely calls to mind the avant-garde cat gut scratching of John Cale, another Welsh “individualist”. After a song inspired by a letter in Cornish from a German Linguist, the set finishes with ‘Eus Keus?’ which translates as “Is there Cheese?”. Gwenno valiantly tries to teach the crowd the lyrics, the results are mixed. No matter, she gives the song everything. It’s not often you get to tap your toe and shake your head to a song where someone’s asking you to bring out the cheese, if there is any cheese to be had, in an ancient and obscure tongue. A mesmerising performance, and a lesson in how to do a support slot properly. Seek out her Le Kov album.

Manic Street Preachers take to the stage after a plinky-plonky electronic musical intro that slowly morphs into a more familiar tune. Nicky Wire looks impossibly cool, as always, and will later go a  bit Vegas with a glittery jacket with his name on the back. James Dean Bradfield doesn’t appear to be interested in taking any prisoners, launching straight into a marvellous ‘The Everlasting’ – all tremolo guitar and air-punching. ‘You Stole The Sun From My Heart’ is similarly coruscating, Bradfield already bouncing around the stage as the crowd of devotees roar their approval, and passionately sing along with ‘Ready For Drowning’ and a crushing ‘Tsunami’ that has Bradfield hopping about again.

This is the opening night of the tour to mark the 20^th anniversary of This Is My Truth Tell Me Yours, still their most commercially successful record. They’ve decided, as Nicky Wire tells us, to take a bit of poetic licence with the running order so that they might spread out the singles. Gigs like this are a treat to passionate fans like the many crammed in to tonight's Olympia. Your favourite band performing your favourite album in its entirety, what could be better? Nothing, and you can see that on the smiling faces around the theatre. The problem for me though is that I’ve always seen the Manic Street Preachers as a brilliant singles band, and some of their albums, this one included - I’m well aware, of course, that over 5 million people disagree with me - aren’t quite the equal of the singles they contain. Bradfield almost admits as much himself when he winces, early in the show, that some of the songs are so serious, and Wire, following the never performed live before ‘I’m Not Working’ remarks “I thought I couldn’t be more miserable than I am now, but listening back to those lyrics, I was worse then.”

Songs like ‘Black Dog On My Shoulder’ and ‘Prologue To History’ (a concurrent B-side) are lifted by Bradfield’s brilliant guitar playing, as is ‘Be Natural’ which takes off about halfway through when the ascending guitar riff kicks in, but they’re just not as good as the singles. Sometimes you feel you’re listening to a manifesto rather than a song, the lyrics' lack of conventional metre forcing the music to jump through jarring hoops. To others, and a lot of them are here, this is a reason to love the band, and good luck to them. Other bands would kill to experience tonight's passionate reaction. That being said, when the album section finishes with ‘If You Tolerate This Your Children Will Be Next’, even the record's most fervent devotees can see the sense in the decision to mix it up a bit. It’s a great song, the sort of anthemic rock that they’re the masters of.

In a welcome “you’ve eaten your cauliflower, now you can have your ice cream” sort of fashion, The Manics dip into their repertoire once the business of the album is out of the way.  ‘Sleepflower’ is fucking ferocious, the stop-start of ‘Your Love Alone Is Not Enough’ has everyone euphoric, and ‘International Blue’ from last year’s very good Resistance Is Futile is the most arse-kicking song about nouveau realist Yves Klein that you’re likely to hear this week.

‘Motorcycle Emptiness’ is just epic, especially that brilliant middle eight. The song is a reminder that the early Manics wanted to be Guns N’ Roses as much as they wanted to be The Clash. You can hear some vague echoes of ‘Purple Rain’ in there near the end too. ‘Solitude Sometimes Is’ and ‘People Give In’ are both strong but overshadowed by a howling ‘You Love Us’, dedicated to Richard Edwards, while ‘No Surface All Feeling’ cops a feel of a bit of Radiohead, or perhaps that should be the other way around given when it was released, not that it matters though as it’s great.

There can only be one song to finish. Bradfield: “You are fucking Dublin. Thanks for sticking with us when the albums weren’t that good. Thanks for coming out on a Sunday night. We are Manic Street Preachers From Wales. This is ‘Design For Life’”. It’s as much a hymn to liberation as it is an anthem, libraries do indeed bestow power. As the crowd sings the “we don’t talk about love, we only want to get drunk” refrain as one, a man near me is close to tears, moved by this music’s – and this band’s - undeniable power.