It was a busy morning at London's Southwark train station and the pressure was on -- but not just for the city's commuters.

In an airy spot between two escalators a small group of musicians unpacked their instruments, checked their music and calmed any last minute nerves.

The London Underground network is holding its first auditions since the pandemic for buskers to keep the city's 3.5 million daily travellers entertained and uplifted.

Actor and singer Peter Willoughby was one of the first to step forward.

As he belted out Alanis Morissette's "Ironic", accompanying himself on the guitar, the judges scribbled notes on their clipboards.

Passers-by rushed past. No time to stop, but the appreciative looks they threw in his direction were unmistakeable.

"I saw the auditions and thought that seems like an opportunity to get back to doing something I loved," he told AFP.

The 35-year-old began busking when he was a teenager in his home city of Ipswich in eastern England, setting him on a path to a career in acting.

"I fully believe in the power of live performance," he said, laughingly adding that as a professional he loved the opportunity for immediate positive feedback.

"I'm very keen on approval," he joked.

- Best of the bunch -

Around 280 musicians from 450 who applied have been shortlisted for the 10 days of auditions which have just begun.

For 62-year-old saxophonist Andrew Bruell from Essex, to the east of London, the auditions are a chance to see if he can cut it along with London's finest -- just nine years after he started playing.

He took up the sax along with his daughter just before he took early retirement from a high pressure managerial job for car manufacturer Ford.

"She had the lessons but I practised and that's what made the difference," he said.

He took to it so well, in fact, that friends quickly started suggesting he do it professionally.

Now, as part of his "second life after retirement", he busks for charity in the street and also performs at parties and gigs.

The auditions, for which he played Prince's "Purple Rain" and the Louis Armstrong hit "What a Wonderful World", are a way of stopping "anyone who isn't really good from performing on the Underground", he said.

"It's a way of getting the very best people," he said, adding that he'd be proud to be selected.

The shortlisted performers will be put through their paces at several stations including Blackfriars and Canary Wharf by three-strong judging panels made up professional musicians alongside station staff.

- Stage presence -

They will be assessed on a combination of musical ability and stage presence, according to Transport for London (TfL) which runs the underground network, with no upper limit except on the number buskers who can be accepted to play.

The licensed busking scheme has been running for over 20 years with auditions held every few years for the around 40 pitches.

The salary is uncertain. Bruell said he does not always get his train fare from Essex. But the important thing is to get your music heard.

Most are located on the Underground but there are also a few on the Overground train network which serves this city of nearly nine million people.

One existing busker, who goes by the stage name Angie G, said many of her fellow performers never returned after the Coronavirus lockdowns in 2020 and 2021.

She said she kept going through the pandemic, busking "anywhere I could find human beings" and urged other people to get involved.

"I feel as a musician it's very good to busk -- not just for the public but for your own mental health," she said.

The judges selections are due to be announced towards the end of March with the new cohort up and running and entertaining London travellers by November.

"Music is just part of our DNA in London," said Justine Simons, deputy mayor for culture, underlining the city's musical credentials from "big stadia to grass roots music all around".

"And for the travelling public it just brings real joy to your journey," she said.