A 10 man film crew captured the storming performance

With a few cryptic clues posted to her social media on Sunday, it was obvious Courtney Barnett had something special planned for London ahead of her appearance at Green Man Festival this weekend.

One of our photographers spent the whole of Monday scouring Facebook and Twitter for clues as to where this ‘secret party’ was. Luckily, one twitter detective had spotted that her latest Instagram post had the location turned on – placing her right outside Camden Town tube station.

Hopping onto the Northern Line without further delay, he arrived just as Courtney was running through the first take of her new single 'Nobody Really Cares if You Don't Go To The Party'. The crowd seemed to be mostly bemused tourists, But there were a few fans dotted around – easy to spot as they were singing along to every word.

Performing under a giant billboard bearing the name of the new single, she ran through the song a few more times, with a film crew of about 10 capturing it from every angle possible.

After the director seemed happy, Courtney addressed the rest of her band – "shall we do a few more songs then?" before launching into ‘Lance Jr’ from her 2013 release The Double EP: A Sea of Split Peas.

This was followed by 'Depreston', 'Avant Gardener', 'Dead Fox', and closed with the lead single from her new album, 'Pedestrian at Best'.

In between songs she engaged with the crowd, talking about her musical beginning as a busker – "The first time I went busking I earnt about $100, although every time after that we earnt nearly nothing, so I stopped after a while."

Mid set, she put out a hat to collect money, in keeping with the busking spirit of the set. There was even a man – not connected to the band in any way it seemed – who played harmonica throughout the entire set.

The crowd were disrupting traffic slighlty by the end, but this didn’t seem to affect the fun and spontaneous atmosphere that follows the Australian wherever she goes.