Music echoing along the corridors as commuters hurry for their train is all part of the experience of catching the metro in any big city.
In Paris, however, busking in the Métro can be a genuine stepping-stone to fame as artists are carefully selected by the Paris Transport Authority, the RATP, which has links with festivals and record labels.
As the authority’s artistic director, Antoine Naso, points out - the Métro is the biggest stage in Paris, with more than five million passengers a day.
Big names that have started their career there, including singer-songwriter Keziah Jones and the winner of the French version of The Voice, in 2016, Clémént Verzy.
This month (October) about a thousand hopefuls will perform in front of a jury which will allocate a licence to 300 artists.
The licence gives them the right to play at any time, in any place, for as long as they wish, for no charge – and they can leave a cap or bucket in front of them to collect money.
Another set of similar auditions will take place next spring. Some buskers will keep their licence while some will be replaced.
Mr Naso started the scheme 21 years ago. He said: “There have been buskers in the Métro since it was built but at first they were illegal and a nuisance. So we created this scheme to improve quality.”
Auditions are open to any musician. The jury looks for technical ability, originality, and tries to represent a variety of music from rock to classical.
“I am impressed by the standard of the musicians,” said Mr Naso.
“They are mostly but not exclusively, young, between 22 and 30.
“And although most are French, we attract musicians from all over the world as they pass through Paris.
“Above all, we are looking for something that will please passengers as, first and foremost, we are a transport authority.”
He said buskers would not usually make enough money to live on but it gives them an opportunity to improve their skills: “It is harder to play on the Métro than on a stage where you have a static audience.
“Artists have to really work at attracting the attention of the public, who are often in a hurry to catch their train. The experience allows them to find out which of their songs work with the public.
“The passengers appreciate the music – every day we have emails asking to be put in touch with one of the musicians to play at their wedding or another event.”
Musiciens du Métro (musiciensdumetro.ratp.fr) works with big Paris festivals such as Rock en Seine and Solidays and last year celebrated its 20th anniversary with a concert at the prestigious Olympia venue.
Hugo Barriol, 29, has been called the Cinderalla of the music world, with his rise from obscurity to a career in music via the Métro.
In 2016, he won the Metro Music Award, in which passengers vote for their favourite underground busker.
He has since shared concerts with French singer Alain Chamfort and released his first e-album with record label Naïve after their director, Marie Audigier spotted him playing his guitar and singing his new-style folk music in the Métro.
Now he is recording his first album in London. The record, in English, is due for release in early 2019.
He told Connexion that he decided to play in the Métro because he thought it would be the best way for an unknown musician to make contacts with music professionals: “I had been travelling in Australia to improve my English and played the metro there.
“When I came back I decided to make my career in music and thought this would be the best way. For two-and-a-half years I played for four hours a day, five days a week.
“First I also worked as a waiter, but then opposite my restaurant was British musician, Benjamin Clementine, and I could see him at his window, playing all day long. So, I decided the best way to progress was to spend all my time playing.”
He said it was strange at first: “You play, but most people hurry past and it is only occasionally that someone stops. You get used to it, though.
“There are good acoustics and you really work at your music and discover what pleases people. My favourite spot was Pigalle and I spent a lot of time there.
“Then the Naïve record director heard me on her way to and from work and now my career has started for real.”