A nod of the head and a wry smile and they're off, fiddles hopping, feet stomping and the gravelly voices belting out the tunes. Music seems to run in the blood of the Irish and once you set foot in the Old Sod, it seems you're never more than a stone's throw from a session.
For all but the most ardent disciples, it's the lively atmosphere that matters as much as the music – the friendly banter, wild stories and back-slapping good cheer of a pub session are like nothing else on the planet.
Here are our some of our favourites for the best craic agus ceol (fun and music) in the country.
Fleadh Cheoil na hÉireann, changing venues
Held in late August, the Fleadh is the mother of all Irish music festivals and attracts about 250,000 people over eight fun-filled days. You'll have to qualify to enter the music, singing, dancing and yep, whistling, competitions but really they're only part of the story. It's the impromptu evening sessions, rowdy sing-a-longs, concerts and céilís (traditional dances) that really draw the crowds.
You'll find trad music session in pubs all over Dublin, from the manufactured craic in Temple Bar to the folksy tunes in ever-popular O'Donoghues, but if you want to see some serious musicians head for Hughes (19 Chancery St, Dublin 7; 01 872 6540) near the law courts. Expect a decent pint, excellent sessions, set-dancing and shaggy-bearded locals with misty eyes.
The Crane Bar, Galway
The music at the brightly-coloured Crane is just as it should be: no egos, no pretension, just addictive, toe-tapping rhythms and a heartfelt love of the craft. Few pubs have space to dance but the atmospheric old Crane is an exception and is the best place in Galway to catch a céilí in full swing.
Willie Clancy Summer School, Co Clare
Some of the best musicians in the world gather in Miltown Malbay for Ireland's largest traditional music school. Along with the expert workshops at this eight-day event are lectures, recitals, céilís and exhibitions. Day and night the pubs are jammed and music comes from every direction as informal sessions pop up in the town's bars and spill out onto the streets and into people's homes.
De Barra Folk Club, Clonakilty
Flutes, fiddles, bodhráns, pipes and mandolins cover the walls at this temple of traditional music in Co. Cork. De Barra's with its vibrant but easy-going attitude offers intimate gigs in the sitting room (really), a purpose-built auditorium and a long list of big-name regulars.
Tucked away in the wilds of west Clare is a one horse town with three great music pubs. Lots of musicians live in this uniquely rocky area and MacDiarmada's is the locals' favourite. If it's standing room only head for nearby McGann's or O'Connor’s, though there's no guarantee of a seat there either.
An Spailpín Fánach, Cork
Sitting just across the road from the Beamish brewery, you're guaranteed a decent pint at the old-world Spailpín Fánach, The Wandering Labourer, (28 South Main St, Cork; Ph: 021 427 7949). Much loved by locals for its laid-back sessions, open fires and snug corners, it's the place to quietly nurse a pint, join the craic or just nod in the corner and let the melody waft over you.
Tí Joe Watty's, Kilronan
Take a trip to Tí Joe Watty's on Inis Móir, the largest of the Aran Islands, and you're almost guaranteed a jig. This is one of the island's oldest and most traditional pubs, with trad sessions every night in summer and a mellow atmosphere that's lets the tourists shake a leg. Purists might object to the come-al-ye attitude but there's no arguing with the music.
Leos Tavern, Crolly, Donegal
The enigmatic, undulating rhythms of Enya and Clannad wooed the world in the 1980s and Tábhairne Leo (Leo's Tavern; www.leostavern.com) is where their sound was born. Set between the Atlantic Ocean and the rugged peak of Mount Errigal, it's a place for legendary sessions and glitters with the gold and platinum discs of Leo's famous children.
For more information on traditional Irish music and culture, festivals, events and gigs visit www.comhaltas.ie.