Even back then, Bagatelle were celebrating an era that had already passed.
And when Summer In Dublin hit the airwaves in 1980, the nation embraced this ration of instant nostalgia like pilgrims clasping a sacred relic.
Liam Reilly's song clearly had what music industry moguls call the X factor. It affected people in ways most disposable pop songs didn't come near. Within weeks of its release, Summer In Dublin had become more than a mega-hit. It became an anthem.
Reilly was a piano player who knew his way around the Elton John songbook. His mates had served their apprenticeship in bar bands. Together they'd been schlepping around for a couple of years before Summer In Dublin transformed their fortunes.
The song opened doors to major venues and the group quickly became the envy of ambitious young local bands, including U2, whose Larry Mullen Jr would later quip that he'd referred to them as "Bag-a-money".
Reilly's song was the modern pop equivalent of Pete St John's Dublin In The Rare Auld Times.
Instead of vanished landmarks such as the Pillar, the Met and the Royal, Bagatelle invoked sights, sounds and smells we were all too familiar with.
The 46A bus, noisy jet planes, a crowded Grafton Street and the open sewer that was the river Liffey. But just like childhood holidays, the picture conjured up was of a bright, warm summer's day. The river was particularly odious on hot days.
No doubt when we hear the song's singalong cadences, we imagine a rose-tinted capital city. Not the dilapidated, economically mismanaged dump it was in 1980, when Charlie Haughey warned us to tighten our belts as the dole queues grew longer and school leavers had little option but to go abroad in search of work.
Thirty years later, you might believe the old French saying: "The more things change, the more they stay the same."
The beggars are still on horseback as the country is saddled with unimaginable debt and the prospect of another wave of mass emigration.
The skyline has changed of course. The Liffey has a few more bridges over it. And much of the docklands is covered in shiny big buildings that will be keeping NAMA busy for a while.
But, being Irish, no matter how bleak things get, we'll still have a song in our hearts. And Bagatelle's Summer In Dublin is one of those timeless, feelgood jingles that brightens the mood.
Curiously, the lyric tells the story of someone who wants to get out of the city, to a place where there isn't much traffic. A place where you can hear the wind, the birds and the sea. It's a yearning for the kind of peaceful retreat that Charlie Haughey found when he acquired Inishvickillane.
When Bagatelle released their song on a 7" black vinyl single (207811 Irl) in 1980, it was to a world of pirate radio and Radio 2 "comin'atcha!"
It was an era before downloads, ringtones and even CDs.
Punk rock had come and gone. New Wave bands were mutating. And the New Romantics were getting into their stride.
In this environment, safe, unthreatening Bagatelle were never likely to challenge The Blades, Microdisney or The Virgin Prunes in the affections of the critical elite.
As a member of Bagatelle once remarked, "The song is everywhere. Like Kellogg's Cornflakes, it's in everybody's home. But no one is raving about it."
Yet Summer In Dublin now ranks alongside The Pogues' Fairytale Of New York and U2's One as one of the best loved Irish pop songs ever.
And that's its own just reward.
Because Bagatelle were maverick rock'n'rollers at heart. There's a clue in the song's narrative.
When Reilly sings "I was singing a song I heard somewhere, called Rock'n'Roll Never Forgets...", he was referencing Bob Seger, the no-nonsense American rocker whose song Rosalie Thin Lizzy recorded.
It's tempting to think that "the drunk on the bus" who told Reilly "how to get rich", has bought the song and contributed to the band's royalties. It's the stuff of pop dreams. Whatever the weather, we'll always have Summer In Dublin.