It comes after the Shape of You star announced in February that his foundation would award the group three years of funding.

Youngsters performing alongside the seasoned artists said it "meant the world" and hoped it would help launch their careers.

London-based AG is known to draw big names for his impromptu performances, which he announces at short notice on his social media channels.

He said giving young talent a platform was "extremely important" to allow them "to shine".

He said: "It's not about me, I'm just a facilitator showcasing talent, trying to help, do my part, giving it everything and hopefully everyone had a good time."

The event also saw TRACKS release their new single called Spotlight, from seven of their students.

TRACKS performers Max, 16, and Jayden, 13, said joining Sheeran and AG made them feel like part of the music community.

"It was insane, words cannot describe how good it was, it was just mad," Max said.

"You get nervous at the start when you are with big people like this, but it actually feels quite good to be doing this," Jayden added.

"I was so excited. I've never met him in person before and he's one of the nicest persons I've ever met and I mean that from the deepest point of my heart."

TRACKS, a collaboration between Sheffield Music School and Sheffield Music Hub, was awarded funding from the Ed Sheeran Foundation earlier this year.

The group's music facilitator Louis Barclay said the money would help fund a youth club and more alternative provision for young people in the area.

"It started with Ed visiting TRACKS and seeing what we do," he said.

"I think he just felt the ethos of what we do and saw it was something he wanted to support."

Onlooker Kim Simpson, who has been following Sheeran's career since his early busking days, said she hoped the gig would give the north "a little bit more of a name" and get young people involved in the city's music scene.

"What he is doing, getting young rappers out performing, supporting them to bring on a new generation of musicians - it's perfect to come and watch," she said.

When I arrived outside Sheffield Town Hall on Sunday evening, a small but curious crowd had gathered around a lone DJ playing a set.

"What is this about?," people murmured.

Soon, the crowd began to swell as rumours spread that a 'big name' was about to appear.

Some could not quite believe it, with one woman exclaiming: "Ed Sheeran, here? Are we talking about the same Sheffield?"

Not long after, the singer emerged, smiling as he was met with thunderous cheers, before casually taking his place beside DJ AG.

For the next three hours, the pair kept the crowd buzzing, putting the spotlight on young talent and giving Sheffield a night to remember.

Busker Blue Bax said he was a "massive" Sheeran fan, adding the musician was an inspiration for him.

"He's the reason I picked up a guitar, he's the reason I picked up a loop pedal at all," the 21-year-old said.

"When I found out about this, I immediately rushed over."

Sheffield City Council leader Tom Hunt, who was also among the crowd, described the three-hour event as "brilliant".

"It really underscores the fact that we are a music city with an incredible pedigree of artists coming out of the city but, more importantly, that we are bursting with talent," he said.

"There are so many young people, performers in doing all sorts of music in this city, who, if given the spotlight, like they're being given tonight, will go on to shine."