His eyes are misting up, now streaming tears. It's a great television moment, except there are no cameras to record the occasion: the opening of a time capsule lost for the best part of 40 years, and a piece of New Zealand history.
The songwriter, the recording engineer, and the musical arranger are sitting at a recording console at Herne Bay's legendary Stebbings recording studio, where so much classic Kiwi pop was laid down in the 60s and 70s.
The switch is flicked and out bursts a luscious piece of 1970s pop perfection, until now thought gone forever, recorded over or erased or biffed out like so many of our seminal recordings. It's a poignant scene that will replay itself over the next few days, as the trio revisit and remaster the tunes for a forthcoming compilation.
They're listening to the work of John Hanlon, one of this country's most successful acts of the 1970s, a singer-songwriter with more awards and chart hits than any other of his generation, but one who - until now - had almost slipped off our compass.
Who of that generation can forget the nagging catchiness of Damn The Dam, or its successor, I Care, or the No 1 smash hit Lovely Lady, all sung in those distinctive sandpapery vocals? Hanlon was huge, and justly celebrated, winning Songwriter of the Year three times in a row at the equivalent of the NZ Music Awards, along with APRA Silver Scroll awards for Lovely Lady and Windsongs.
And yet Hanlon is almost forgotten, his pop landmarks left off lists of greatest Kiwi hits, and seldom mentioned. Why? Because John Hanlon pulled the plug on his career and, for all intents and purposes, turned off the lights and disappeared.
Jumping the ditch for a high-powered and lucrative career as an advertising "creative" in Sydney, Hanlon continued writing songs on the sly, but it took his grand- children's recent discovery of his past life as a singer-songwriter to give him the incentive to revisit the past, and to work on the first authorised re-issue compilation.
"After I decided to walk away from music, I never talked about it," says Hanlon. "But my grandchildren saw this TV show, which listed everything I'd done. They said 'are you a songwriter?' and I wanted to say to them, 'I wasn't just a songwriter, I was the first hugely successful singer-songwriter in New Zealand'."
Born in Malaya in 1949, by age 19 Hanlon had a wife and child and was working in New Zealand's formative advertising industry, soon to become an ambitious creative concept director for WHT, and later, creative director for Bob Harvey's MacHarman's agency.
It was at a small gathering late one night in 1972 that Hanlon was cajoled into performing. Until that moment, Hanlon's songwriting had been a furtive, solitary activity and, as he was self-taught, he knew only his own songs, all of which were scrawled in a school notebook.
"Somebody had gone past my Kombi and seen my guitar. I agreed to play, and brought this little exercise book out. They kept on saying 'play another ...' and when everyone got exhausted and went to sleep, a guy who was sitting in the corner said 'I own a recording studio in Auckland', and I thought 'sure you do'."
The man with the sunglasses said: "My name's Bruce Barton, and I own Mascot Studios. Give me a call when you get back to Auckland."
The rest is history, but the first album, Floating, tanked. Damn The Dam changed all that. Originally a radio ad for Pink Batts designed to lobby the Government to make housing insulation mandatory, it was released as a single and, like the fantail in its lyrics, the song flew up the charts, and became an unexpected anthem for the environmental movement.
Surprisingly, Hanlon was never explicitly involved in the Save The Manapouri campaign, although the widespread use of his song must have edged it towards the success it achieved in saving the Fiordland National Park islands from flooding.
In 1974, however, he was involved in the Labour government's "I Care" environmental initiative, performing the theme song at its outdoor launch, but still reels at the cavalier treatment he received from the stiff-shirted politicians of the day. "I ended up going ballistic. It was a 'hello darling', pigs at the trough cocktail event."
Hanlon's reputation for not taking stuff and nonsense lying down would also alienate him from the powerbrokers in television.
It all started with his refusal to sing and wag his tail to other people's songs. The situation was exacerbated when the NZ Broadcasting Corporation banned two of his songs: Is It Natural? for a line about a "randy schoolboy", and Crazy Woman for daring to mention a lady of the night.
"When Crazy Woman was banned, I just lost it. It was a true story about standing and waiting for a taxi outside the old NAC [airline] building. I was in a line with a priest and this drunk woman, who was obviously a working girl, said to the priest 'you could do with a root'. And so this becomes 'and she offered her services to a Catholic priest, he blushed and walked away'. Not one swear word and it was banned.
"My manager said 'you've got to apologise', so I had to sit in this room with all these cardigan-wearing dicks, apologise and promise to be more respectful in the future, because they were the guardians of good taste. This was the world we lived in!"
His biggest hit, Lovely Lady (1975), came out of a determined ruse to get himself back on the box.
"I couldn't get on television and that was causing my record company enormous angst. There was a songwriting contest called Studio One and I entered the same song they turned down the year before, and they accepted it. Every week they'd say, 'and still standing is John Hanlon's Lovely Lady', and I was there with my awful shirt and glasses. Even at his commercial peak, though, the novelty was already wearing off.
"Imagine this: three nights a week you go out to a dinner party and you get to tell eight jokes, the same eight jokes every night. Try that for a month. Now a year. And every time you start to tell the first joke, somebody's yelling out for the third joke. I'd gone from this really interesting, alert audience to people who came to hear the hits and see the guy, and I wasn't that guy."
His gentle, melodic songs made him our own Donovan or John Denver: gifted, but hardly hip.
He was in awe of the fledgling Split Enz, so much so that he agreed to perform with the as-yet unknown band in Whangarei to generate an audience. "But when I went to wish them luck before the concert, Bryan [Tim] Finn wouldn't even talk to me. He had such disdain for me that I've never been able to forgive him."
Being saddled with environmental credentials also meant that he was hauled out to sing at every conceivable protest, and it was one such demonstration against the nuclear-armed warship Truxtun that finally broke the camel's back.
"When I came to address the crowd gathered at Aotea Square there were all these anti-American banners up. I got up and said 'I'm not going to sing, and I'm not even going to talk, until you take all those signs down'.
"Well, there was booing and hissing and objects were being thrown. I said 'look ... Russia, China, America ... all nuclear powers but only one of those countries lets you have a demonstration like this. Only one of those countries defends free speech'."
Over in Sydney, a new life beckoned: "Selling self-saucing sponge puddings in a can. Was that a good thing? Probably not. Was it fun? Yes it was. Did I eat them myself? No I didn't," says Hanlon of his time in advertising.
Having now retired from the ad game, Hanlon's focus is again on songwriting and he hopes that the re-issue will at last give him a modicum of respect in the country he plans to return to live next year.
"As I say in my liner notes, here it is guys, my name is John Hanlon, I'm a Kiwi songwriter. Always was, always will be."
• After The Dam Broke is out on Ode Records.