Beta BandVicar Street, Dublin★★★★☆Back in the late 1990s the Beta Band delighted in defying the conventions of the music business, so it’s more than mildly jarring to encounter the cult indie group at Vicar Street in Dublin indulging in the biggest cliche of them all: the heartfelt reunion.Heartfelt is just the word, too, as these four now middle-aged musicians clock in with an emotive set that brims with singalong moments and has an audience streaked with grey partying like it’s literally 1999. That was the year the Beta Band released their self-titled debut album only to immediately disown it as “f**king” awful and “probably one of the records that will come out this year”.In their defence, the LP was no classic (and it’s glossed over almost entirely at Vicar Street). But their public disavowal also spoke to a contrarian streak and a determination not to be seduced by the music industry’s late-1990s love-in with indie rock. (To their apparent horror, the launch party for the Beta Band was attended by luminary luvvies such as Noel Gallagher and Richard Ashcroft.)They remain cheerfully bloody-minded as they re-form after a 24-year hiatus. The lesson of this exhilarating show is that rules are made to be broken, conventions to be upended. Hence the unorthodox start time of 8.30pm, their arrival to the random strains of David Bowie’s Memory of a Free Festival and the decision to omit their best song, Dr Baker. The equivalent would be Oasis rocking up at Croke Park and not performing Don’t Look Back in Anger.As Bowie’s voice fades, it’s straight into the uncanny valley when a man who looks like Louis Theroux in a boiler suit arrives to manipulate a sampler. This is the Beta Band keyboardist Robin Jones, soon joined by frontman Steve Mason and the rest of the group on the oddball lurch of their opening tune, Inner Meet Me.The song is the Beta Band in miniature. Mason wears a mad-for-it bucket hat but avoids eye contact and sings like a sea dog relaying a fantastically and potentially made-up yarn about his voyages.Along with the Scottish boundary-pushers Board of Canada, Beta Band were pioneers of the hauntology aesthetic, which repurposes dimly recalled memories of 1970s childhoods as clean-burning nightmare fuel. That is the vibe on the splendidly spooky She’s the One and on the unsettling Needles in My Eye, which splits the difference between Wonderwall and the Wicker Man.It’s the duty of all experimental bands to test the patience of their audience. The Beta Band do not disappoint, getting stuck into their conga drums at every opportunity. Did they re-form as an excuse to pound out a groove to their heart’s content? Whatever the answer, they don’t dance around the fact that forays into the outer limits of congadom are to the Beta Band what crotch-waggling guitar solos were to Led Zeppelin.Amid the drums, Mason dances like a demonically possessed dad while occasionally standing on a riser to loom over the crowd. So assured is their boundary pushing they can even scuff up their biggest hit, Squares, by removing the whimsy of the original and turning it into a hard-edged onslaught.They close the encore with the fever-dream indie jam of The House Song and, inevitably, another thrill-a-minute drum solo. How wonderful to have these brilliant boffins back, still playing by their own wonky rules.