U2 surprised students at their old school Mount Temple and the shoppers of Grafton Street on Friday as they celebrated forming 50 years ago.

Ahead of the release of their latest studio album, Carnaval De Luz, Irish band U2 have been celebrating a big anniversary.

The group has been together for 50 years, and what is rare in a band with their legacy, all four original members are still involved.

Speaking on their monumental anniversary on The Pat Kenny Show, arts journalist Pat Carty told host Ciara Doherty that yes it is a strange fact, but that doesn't mean it's always been smooth sailing for the group.

Mr Carty shared: "That is strange and that's almost unique in bands. I was thinking of maybe ZZ Top, but unfortunately, a couple of those guys have gone to their reward [have died] at this stage.

"So for a band to be together that long, obviously, they trust each other, they love each other. Do they fight? Of course they do.

"I think Bono has said a few times that they've broken up a hundred times. They just haven't told us about it and get back together.

"One famous one, I suppose, is the Achtung Baby recording sessions weren't weren't going swimmingly, really, in Berlin, and they came close to knocking it on the head.

"And then a song called One just popped up out of nowhere and the age joked that, well, that's the summer house taken care of anyway.

"You work with people. I work with people. I mean, you wouldn't want to be around them all the time, really, you know? But 50 years? It's remarkable."

The band also payed homage to their anniversary by choosing their debut single, I Will Follow, to open both sets at Mount Temple and Bewelys on Grafton Street.

It was the first song off their first album, and as Mr Carty put it, it was "the hit that really never was".

"It still obviously means an awful lot to them and you can see the reaction of the crowd. It's a song that... it's of its time. And yet it's kind of timeless."

Something that fans are greatly looking forward to with the new album is hearing the song Torn, which features the final recorded vocal performance of Dolly Parton.

Dolly died after a short battle with cancer aged 80 on August 25, and the band recently revealed she had joined them on the upcoming album.

The song was co-written by U2, Parton and Irish songwriter Johnny McDaid, and explores broken family ties.

Main image: U2 perform, Picture by: PA Archive/PA Images