There are some nights that illuminate your mind for a long time afterwards. A Sunday in January at the National Concert Hall. A packed room exuding expectation and excitement, giddiness and wildness. A band of masters and maestros playing out of their skins, soaring and swinging and sweeping all before them to roars from the aisles. Ladies and gentlemen, we are floating in space and we don't want to come down.

That was The Gloaming introducing their self-titled debut album. Here was a sound with breadth and depth, a sound informed by trad and jazz and rock and classical, a sound powered by cinematic ambience and exuberant energy.

There was no need for The Gloaming to make introductions. All five have considerable skin in the game. There's the east Clare fiddler Martin Hayes, a man steeped in the tradition who has taken that music far from home and is the Gloaming's chief-of-staff. There's Dennis Cahill, the decorated Chicago guitarist from Dingle stock who has been Hayes's wingman for years. There's Iarla Ó Lionáird, the voice from Cúil Aodha, who has adorned so many albums and collaborations and great artistic statements over the years. There's Caoimhín Ó Raghallaigh, the Dublin-born fiddle player with a curious ear and a winning glint when it comes to adventurous sounds, be it solo or in collaboration with Triúr and This Is How We Fly or a myriad of players such as Brendan Begley and Mick O'Brien. And there's Thomas Bartlett, the Vermont pianist and producer known as Doveman, who has worked and performed with acts such as The National, Antony and the Johnsons, Yoko Ono, Nico Muhly, Sam Amidon and many more.

It was Hayes who put the group together, not for one last job but for a much different job of work, although he wasn’t sure what would happen when the assembly began to play. “I was going to see how it went,” he says. “I had good faith in all these people. I knew them all individually, and I had played with all of them, and I knew their taste and their musical aspirations.

“I knew we could get the moody ambient feel. As to whether we’d get the energy and muscular liveliness, that was by no means certain. There was an unpredictability. But it’s like putting together a good meal: if you get really good ingredients and you don’t mess with them too much, you’re halfway there.”

Hayes knows this was no guarantee that the method would work. “Just as we were getting into it, there was a feeling around the band of, Let’s not f*** this up, let’s give this a chance, because it looks like it might work, so let’s not make too many big mistakes.”

Bartlett says it was Hayes who had the map. “Martin seemed to have so much confidence in the idea that it was all going to work. I truly felt I was along for the ride on this one. Working with Martin and Dennis was just a thrill, having being such a big fan for so long. With Caoimhín and Iarla, their music was new to me, but I felt an immediate response to them and felt very comfortable playing with them.”

Ó Raghallaigh first felt that this new band was something else after the initial recording sessions. “Listening back to the early mixes was the very first time I really had any sense of what the music was and what it offered. When you’re in the middle of it, playing your part in it, you really don’t have a handle on what it’s like to experience it as a listener. Hearing the proper mixes suddenly clarified for me what it was and what it could do.”

Feel before precision

There wasn't that much of an agenda, Hayes says. "Everyone was free to fire in what they wanted. There was one agenda I had in my mind, which was based on a book of Japanese aesthetics called wabi-sabi that I wanted to share with the band at the time. It was about not worrying about little errors or mistakes – more about feel than precision, more about the general direction and thrust of the music. That's a very light agenda."

The reaction to the album has been hugely positive. “It’s been a totally lovely, pleasant surprise,” says Bartlett. “Having my parents listening to it a lot has been amazing; they love it and they’re picky.

“I’ve worked on various projects for a very long time, and sometimes I feel really confident that they’re going to do really, really well – and then there’s barely a blip. Other times I don’t think that much about it, and they’re the ones which get all the response. At this point I’ve given up predicting how something is going to do.”

If the recording was a statement of intent, the live shows have been declarations of independence. Anyone who has seen The Gloaming live this year, be it in Dublin or at Other Voices in Derry, the Ceiliúradh in London or the Womad festival, can testify to the fierce, raw, transcendental power of the performances.

Yet these concerts have been comparatively few and far between. The band have played nine shows this year so far, a surprisingly low tally for a band plugging their debut album, even if it’s a supergroup.

Hayes puts this down to other commitments. “That’s the one disadvantage of having really great musicians with all their own careers on the go,” he says. “You can’t corral them, and no one wants to abandon their own projects – and it’s important that those projects also succeed. It’s important that we turn a disadvantage of not being able to tour all the time into an advantage of not having to do a whole bunch of things you don’t want to do either. You can be choosy because you have to be.”

Ó Raghallaigh says, “We could be touring nonstop if we wished, becoming jaded warriors of the road. But this way, with the small number of concerts in really special venues, it makes every single concert feel special, a real opportunity to make something beautiful happen, a chance to collectively find some magic in the cracks between the music.”

The live show is where things have come together. There have been times, for instance, when Tom Doherty's Reel from Opening Set becomes a wave of music capable of taking your head off, a groove with an allure for techno as well as trad heads.

Hayes says an improvisational fluidity means pieces like this will unfold in different ways on different nights. “We don’t want to plan things too much. You might wake up the next day and go, ‘Remember that thing we did? Let’s do that again.’ And that would be the death of it.

“Every night there are moments when the band take off on a riff somewhere that we hadn’t planned and it suddenly takes on a different energy. There are, broadly speaking, very clear arrangements there, but if you have an idea, even an idea which alters all of this, throw it in.”

Standout shows

Certain shows stand out for the band. "The last show at the National Concert Hall at the end of January was really beautiful, I thought," says Ó Raghallaigh, "really satisfying for me musically, and such a wonderful reception. The night before in Union Chapel, though, was totally overwhelming, like being inside a rocket ship taking off."

Bartlett also has a vote for that London venue. “It’s a great space – this is a good band to play in churches – but that was one where we tried out a lot of new stuff, and everything was gathering together in a way which was both exciting and out of our control, which is a nice feeling.

“The very first one, too” – at the National Concert Hall in August 2011 – “was memorable. I knew the reputation of everyone involved, but the fact that it sold out before we played a note of music for anyone was kind of insane.”

Hayes recalls a show in Belfast, too. “We got into this slow, building, grinding rhythm that I like, and I think suits us. I went, oh yeah, I know what we’re good at now.”

The next stop for the band is Kilkenny Arts Festival. They play a sold-out show at St Canice's Cathedral, and individual members will also lead the Marble City Sessions, with guests such as Bill Frisell, Sam Amidon, Dan Trueman, This Is How We Fly, Doug Wieselman and Ghost Trio.

“This thing in Kilkenny,” says Hayes, “is an attempt to pull the loose threads of all our connections and different worlds together. Bill Frisell, for example, would be a bit of a father figure in the minds of The Gloaming and associated friends. We would all have a great respect and feeling for him, and he’s someone we could all relate to.”

New material

But it’s a future date in a recording studio that holds the most appeal for the musicians. Hayes points out that their current set is “stuff which we worked on in the first week we got together”, and he’s eager to move on to work on new material.

“We need some opportunities to explore and develop,” he says. “We’re working off the first baby steps of the band. I think clearing the slates and coming at it knowing each other a lot better, and knowing where potential exists, means we could do a lot more.”

A new album also appeals to Bartlett. “Every time we meet back up has been great. It’s nice that it wasn’t a case of, put out the record and then tour, because I get sick of almost anything very quickly. There’s nothing tired about it yet. And a couple of days ago we were talking about doing another record, which is really exciting.”

Ó Raghallaigh adds, “There’s a real feeling now that it’s here to stay, that it’s not a short-term project, that there’s a shared desire to go further, explore more, dive deeper. The music has its arms wide open, willing to give something beautiful, something fundamentally powerful and true. It’s not afraid and it’s not smug and knowing. We’re on an adventure. We don’t know where we’re going, and beautiful things are born of that.”

For Bartlett, every time he goes onstage with others is a chance to live out some dreams. “It’s such a thrill for me to be able to play the way I like to play and fit into this group. I’ve talked to my friend Sam Amidon a lot about how this band is what my 15-year-old self would have wanted to be doing in a very specific way. It’s a fantasy fulfilled in a really lovely way.” The Gloaming play at St Canice’s Cathedral in Kilkenny on Wednesday. The show is sold out. kilkennyarts.ie