Musicians have long busked in the hopes of making quick cash or getting their big break - and many of the world's biggest stars started out their careers by taking to the streets to share their talent with the world. In recent years, the trend for famous singers going undercover and performing to the public has risen. Whether it's an experiment to see whether passers-by recognise these stars in an everyday environment, or going back to their roots to engage with their fans, here are ten of the best celebrity busking moments.

Donovan

When teenage busker turned X Factor contestant Murdo Mitchell began belting out Colours on Glasgow's Buchanan Street, the last thing he probably expected was the singer of the 1960s hit to join him in a duet. Donovan spotted the 14-year-old singer and performed two more songs with him. Having started out as a busker in his teens, he told The Herald that he saw in Murdo what he had himself in his younger years; "the hunger to communicate."

Bruce Springsteen

Bruce Springsteen was reportedly in Boston to drop his son off at college in 2013 when he asked to borrow busker David Gonzalez's guitar, before treating spectators to a performance of Born to Run. A similar feat happened in 1988 in Copenhagen when he gatecrashed another busker's performance and sang The River and Dancing in the Dark.

Notorious B.I.G

Rapper Biggie Smalls started freestyling in the streets of Brooklyn to hone his craft in his teens. While not strictly busking, Biggie performing in the block he grew up in helped cement his status as one of the most legendary rappers of the Nineties.

Passenger

Passenger, real name Mike Rosenberg, started out in music by busking in his native Australia back in 2009. Now 29, the singer has been known to draw a crowd of hundreds to his street gigs. He had a memorable performance at Buchanan steps in Glasgow last May as part of his busking tour, which helped to raise awareness of homelessness in partnership with Big Issue magazine.

Joshua Bell

Virtuoso violinist Joshua Bell played in the Washington underground for 43 minutes in 2007 on an instrument worth $3.5 million, finishing off with Bach's famous piece Chaccone in D minor. Out of 1097 people, only seven stopped to listen to him for more than a minute.

Justin Bieber

He might be worth £130 million, but Justin Bieber had humble beginnings in his youth busking for pocket money in the streets of Stratford, in Canada. The then 13-year-old singer looks like butter wouldn't melt with his open guitar case full of change, but it was his busking videos that caught the eye of manager Scooter Braun, who helped Bieber become the highest earning celebrity under 30 in the Forbes rich list last year.

Neil Young


 

On April 2 1976 Canadian singer Neil Young and his band Crazy Horse arrived in Glasgow for their concert at the Apollo. They met with a film crew, including director Murray Grigor and the late cinematographer David Peat, to make a video of their time in the city. Before the show, Young sat down outside of Central Station with a harmonica and a banjo and played The Old Laughing Lady for the gathering crowd. 

U2

Irish rock band U2 disguised themselves as ageing hippies to perform in the New York subway for The Tonight Show in May. Thousands of passers-by walked by the group without noticing that they were famous - drummer Larry Murren Jr even used upside down buckets instead of his drum kit for effect - but Jimmy Fallon took off his disguise and announced that it was U2, which quickly attracted onlookers eager to capture the band on video.

The band are no strangers to pop-up gigs; they famously played on a rooftop for the Where the Streets Have No Name music video in 1987, bringing the streets of Los Angeles to a standstill.

Nile Rodgers

Chic frontman Nile Rodgers performed in London's Southbank in June, gathering a small crowd when he began playing well-known singles Le Freak and Everybody Dance. Having been homeless earlier in his life, Rodgers admitted to followers that he used to busk to make a living before he burst into the music scene in the Seventies.

Paul McCartney

Paul McCartney wowed crowds at Covent Garden two years ago in a pop-up show, gathering fans of all ages at lunchtime to the piazza as he sang songs from his latest solo album New. He also busked for film Give My Regards to Broad Street in the mid-Eighties, wearing dishevelled clothes outside Leicester Square station - and not one person recognised him as the former Beatle.

Ed Sheeran

Ed Sheeran's rise to fame is one of the greatest 'rags to riches' stories in modern music. The singer-songwriter was previously homeless and slept on the Tube or on his friends' couches, performing gigs in the evenings to make a living. Now a multi-platinum artist, 'the nicest guy in pop' still stays grounded by surprising fans at weddings, birthdays and even joining young performers on stage for a jam.