JJ Smyth’s exterior spells confidence: recently painted walls of contrasting colours; large, national flags almost draping the building; a large plaque commemorating famous Irish poet and lyricist Sir Thomas Moore, who was born here. When I open the door, my arrival brings cold autumn air and surprise to the dated interior and the handful gathered.

Three young German women are conversing with the barman and it looks serious.

‘Most of them are about 4.2 or 4.3%,’ he says of the beers’ strengths, looking at the taps reflectively.

‘Weaker than in Germany,’ they say.

‘Yes, true,’ he nods. ‘But if you drink enough of these you end up with the same result.’

Their laughter scatters the quietude, a hush that contrasts with the vibrant, lively nights this pub saw for 30 years as unofficial home to Dublin’s jazz. Renowned Irish jazz guitarist Louis Stewart had Monday night residency here. Ex-Miles Davis saxophonist Dave Liebman regaled the place.

We went to the last live gig here in early 2016, a Sunday afternoon session with Nigel Mooney, grandee of Dublin’s jazz scene, who plies a trade of classic guitar and enchanting voice. In 1986, Mooney persuaded JJ Smyth, owner till he sold the pub last year, to give his blues band a three-week trial in the long, dark, upstairs bar, previously used for weekly darts tournaments and occasional lesbian discos.

‘Will the end of jazz here affect how much work you get?’ I asked Mooney that day.

‘Oh, it’s only about 90% of my work,’ he said. For hours that afternoon he brought old pal after old pal on stage to give a swansong, a palpable sense of the curtain drawing on an era. We stood beside an octogenarian Dub who’d ventured into town to be at that final gig. Jazz had always been his thing. It was his homage to the place that had been Dublin’s jazz scene for all those years.

As I take my pint from the bar I ask the young barman why the new owners have dropped the music. ‘Was costing too much to have a barman upstairs for a whole evening just to cater for the gigs,’ he says.

Echoes of lost jazz contrast with the excessive thump of 80s, 90s and beyond bellowing from the sound system. The German girls soon leave and the inescapable, invasive music seems wrong in a bar with a handful of locals and a middle-aged, suited man with dyed black hair who looks like he’s entered the wrong establishment. Red candles held in Gunpowder Gin bottles contrast with the soft green seating, red walls and purple carpets. Little white lamps adorn the wood-panelled wall beyond the bar. It’s late November and the interior ironically feels almost fashionable given it’s pre-Christmas.

A middle aged group enters, shake hands with two frequenters they obviously know. ‘Can I get a dodgy pint of Guinness?’ one of them asks the barman. The additions change the balance between talk and other noises. The German girls return. Another group of tourists enter, ask a local to take a photo of them and another conversation starts.

This is the unpredictability the visitor faces: somewhere that might have no life; or a milieu of ‘old Dublin’ locals in for a no-frills pint and banter, and tourists who’ve serendipitously wandered in. It feels like it oscillates between the two – by the week, by the night, by the hour.

The weekend after I visit the pub I spot an ad for Sunday afternoon sessions by Mooney and accompaniment in a Dublin hotel. Smyth’s seems bereft without the jazz, but the music has moved on. The law of life is change.

Prices (23 November 2016)

Pint of Guinness: €5.20

Pint of lager: €5.70

Measure of whiskey: €5.20

1/4 bottle of wine: €6.60