YEH, God, it’s madness. Paddy Maloney has just reacted to being reminded that Irish traditional musicians The Chieftains are celebrating their 50th anniversary this year.

“Would you believe it?! I don’t know where it all went,” he says, on the phone from Wicklow, County Wicklow. “Even in the 1950s, when I was first trying to put a band together, trying to create a happy sound, who could have foreseen it?”

Piper Paddy is 73 and back on the road with his bearded Chieftains chums, marking 50 years together and the April release of Voice Of Ages, an anniversary album made with a host of new chums: Bon Iver, The Decemberists, The Civil Wars, Imelda May, Carolina Chocolate Drops, Paolo Nutini, The Low Anthem and more besides.

On Tuesday, Paddy’s 12-piece touring band and dancers, but not any of the album guests, will perform at the York Barbican.

“We still go on! It’s the music itself that keeps us at it,” he says. “That’s what we are: good traditional Irish musicians – and we’ve made lots of traditional Irish albums, but importantly we also moved into collaborations.”

Those fruitful collaborations began with Irish flautist James Galway in 1986. “I met him on an elevator in Sydney, Australia,” says Paddy. “Then we started to talk and about six months later, he was back over there and we were back over there, so we decided to record Over the Sea To Skye.”

There followed the celebrated 1988 union with Van Morrison, Irish Heartbeat, an album of trad favourites that sparked new life into Marie’s Wedding, Raglan Road, She Moved Through The Fair and I’ll Tell Me Ma. “Everything was recorded in a week after Van called me about six months before that and said, ‘How about doing a record?’ and I said ‘Fine’,” says Paddy.

The project took a while to come together. “I was in Dublin and I didn’t know Van was in London but we eventually met up and had chats about it. And when I came up with the arrangements, he said ‘Great shapes’, though I didn’t dare tell him how to sing,” says Paddy.

He considers the collaboration with Morrison to be the best in the Chieftains’ catalogue. “It’s the total Irishness in him,” he says.

Come the 50th anniversary and Paddy decided this was not the occasion for another retrospective. “It’s all been done before, so I wanted to do something fresh instead, and the first thing we had to get done was the ‘anchor track’, The Chieftains Reunion, which we did in Dublin last October,” he says.

True to the title, assorted Chieftains through the years did reunited, including two of Paddy’s fellow original members. “Martin [Fay] couldn’t come along but Sean [Potts] and Michael [Tubridy] did, and they’re both in their 80s now. I’m only the baby at 73,” says Paddy.

“It was a great track and I thought, ‘Where do I go now?’. I didn’t want to go back to Van, Sting and The Rolling Stones, and I hadn’t been jumping over the moon about the music acts of the last 15 years, but I got a collection to listen to that included the likes of Mumford & Sons, who were on for the album all right, but then they had to move on and I just couldn’t wait.”

Paddy picked out bands from songs that struck him, always looking for an Irish connection too, and he made the most of his friendship with T-Bone Burnett, who became the project’s co-producer.

“In the end, I did three trips to Los Angeles in six months,” he says. “I’d call on my good friend T-Bone who was already doing things with a lot of the bands, so he asked them to be involved.”

Lisa Hannigan (My Lagan Love), Paolo Nutini (Hard Times Come Again No More) and Imelda May (Carolina Rua) all recorded their contributions in Dublin, as did The Chieftains themselves. The rest were done in California.

“Bon Iver’s Justin Vernon said ‘Don’t let this album pass without me’. We were close to the deadline, but he said, ‘Look, the day I get home I’ll record it’. That was November 19 last year,” says Paddy.

“His contribution arrived in Dublin on the morning of the 20th and by 12 o’clock that night, the Chieftains had done our parts. By five o’clock the next morning I was on the plane back to LA to finish the mastering.”

The album closes with the most unusual contribution… from space. The Chieftains In Orbit features a tin whistle tribute by Chieftains fan and NASA astronaut Cady Coleman. “She asked Matt Molloy from the band if he had a spare flute she could take on to the International Space Station for six months, so she took a flute and a tin whistle,” says Paddy.

What Paddy had in mind was a duet “connecting here and there”. The recording combines a message from space from Cady with her tin-whistle version of the 250-year-old tune Fanny Power, blended in with The Chieftains back in Dublin.

“My son Padraig introduced me to Cady as he’s a rocket scientist and has been with NASA for 11 years – he’s a doctor of nano-physics now,” says Paddy.

Fifty years and rising, will The Chieftains ever stop? “Oh, stop it,” says Paddy. “My wife was asked, ‘Will he ever retire?’, and she said, ‘I think for the last ten years, he’s been in rehearsal for retirement’.

“We did try to slow down but then you get the craic again, the buzz, and you can’t stop. I reckon it’ll be the boots-on job for me!”

• The Chieftains play York Barbican, Tuesday, 8pm. Box office: 0844 854 2757 or yorkbarbican.co.uk