The 60, 70s and early 80s was an extraordinary time for Irish music. A 'revival' took place with bands such as Planxty, De Dannan, The Bothy Band (and many others) emerging, giving a buzzing, new and youthful feel to traditional tunes that had been circling around pubs and sessions over the last couple of hundred years. Andy Irvine (the beardy one) went one further by travelling in Eastern Europe and bringing back traditional Eastern tunes that he seamlessly wove into the Irish sets, to brilliant effect. Here's Paul Brady, Andy Irvine and Donal Lunny with various stringed instruments playing a Mominski Horo.
Take a look at that red haired guy, Paul Brady, who simply couldn't look more Irish if he tried. He sang the best version of one of my most favourite songs (and it's pretty rare that I enjoy a traditional song, I'm far more about the tunes), Arthur McBride. We do it in my band though it'll never be as good as this.