The 1991 gig – a benefit show for the Sick Kids – witnessed one of the biggest rock acts on the planet grace one of Edinburgh’s smallest stages.
And until now, the actual number of images of the fabled event have been thinner than a Krist Novoselic comb over.
That all changed last month when long-time fan Alan Edwards dusted off some old prints and uploaded them to Facebook.
From just one image of Kurt and Dave on that wee stage, Alan, à la Spinal Tap, has cranked the quota up to 11.
Not a soul, save for Alan Edwards and his closest comrades, had laid eyes on the rare collection of snaps since the day they were captured.
The day in question was December 1, 1991 and all the cool kids were head-banging to the American trio’s brand new single Smells Like Teen Spirit.
Whether he liked it or not, 24-year-old frontman Kurt Cobain was hurtling towards a life of distinction as the kohl-eyed king of Generation X.
Back then, Alan, 45, who now lives and works in Los Angeles, was a 19-year-old Forres lad studying engineering at Edinburgh Napier.
A massive grunge fan, he had tried, without success, to get tickets for Nirvana’s sell-out show at Calton Studios two nights earlier.
His disappointment would prove short-lived.
Local group The Joyriders discreetly invited Nirvana to do a benefit gig at The Southern bar, which, back in ‘91, still put the odd band on.
“A friend of a friend knew Nirvana’s tour manager and told me about the Southern gig,” Alan explains. “But it was treated as this kind of urban myth. Nobody knew if it was serious.”
On the strength of rumour alone, Alan and his mate John Grant joined the hopeful line of like-minded folk outside the South Clerk Street venue.
Not even The Joyriders knew if Nirvana, billed as “very special guests”, would turn up.
“The guy from the band that played went up to the microphone and said ‘I’ve been told that they’re not coming’,” Alan recalls. “Most of the bar left.”
Undeterred by this bogus development, Alan stayed put.
“I had this s****y camera and I’m so glad I took it,” Alan laughs. He is now one of just two people known to have taken pictures that night.
When Kurt Cobain and Dave Grohl – Krist Novoselic took the night off – finally strolled through the front door, Alan was very glad indeed.
Their turning up was all the more remarkable since Kurt was in serious pain at the time of the gig, suffering from the same stomach problem that plagued him for much of his adult life.
With Kurt on vocals and drummer Dave on bass duties in place of the absent Krist, two-thirds of Nirvana performed a short acoustic set as an astonished audience whooped and glared before them.
“It was just epic,” Alan exclaims. “When Kurt screamed out the lyrics to his songs, I’ve never heard anyone with a scream like that. He could’ve stripped paint off the walls.”
After the show, Kurt and Dave, to Alan’s utter delight, hung around for a while to stand and chat to punters. “I got talking to them for a little while,” Alan says, after happily snapping away while his heroes performed mere feet in front of him.
“They could’ve went ‘see you later, bye, bye’ and not given me the time of day. They were just super-cool.”
In between chin-wagging with the two superstars, Alan took yet more photos, incurring the wrath of one doorman.
“One of the bouncers was getting angry because I was taking pictures,” Alan recalls.
“Dave Grohl saw what was going on, walked over, kissed the bouncer and gave him a big hug. The irony is I didn’t get the camera confiscated because of Dave Grohl.”
To put it another way, Alan’s photos survived because the future Foo Fighters man intervened. One of the photos shows the two together, Alan giving the thumbs up, and Dave a simple wave.
In another image, a doe-eyed Kurt is captured staring directly at the camera in a small sea of people. It is, without question, the most evocative of the set.
“I was looking at Kurt Cobain and he was looking at me,” Alan says, passionately. “It was like the whole f****** world had stopped.”
He adds: “That picture captures everything about him. His intensity, his soft side, his good energy, his talent. There’s an incredible power in that picture.”
When Nirvana eventually departed, they left behind a couple of dozen Edinburgh souls for whom open mic nights would never be quite the same again.
“The guy from the Joyriders, he should be commended for putting on that event,” Alan insists.
“For me to witness what I witnessed was f****** awesome.
“Without the pictures, you can paint it only to a point, but that one picture of him staring just captures how fragile life can be... just that stare, it just says so much.
“I was there. It was a wonderful experience and a great night and it’s something that will stay with me for the rest of my life.”