First Aid Kit harmonise with pupils at the Albert Hall
In a room lined with huge photographs of the greats who have filled the Royal Albert Hall in the past, the Soderberg sisters, also known as First Aid Kit, lead a singing workshop for girls from local schools.
"As a young woman there are so many things you are told you can't do," says Klara
"Our message is always to do it."
The folk duo, who grew up in a suburb of Stockholm, started writing and performing together just seven years ago, aged 14 and 16. On Wednesday they will be playing the Albert Hall themselves.
"We went ahead and started writing and performing our songs."
The sisters particularly wanted to deliver a workshop for young girls.
"It's really nice for us to get to meet the girls. And because we started out at the same sort of ages as they are now, they can relate to our story," says Johanna, now 23.
The workshop is part of the Royal Albert Hall's education workshops programme, which brings rising stars into contact with aspiring teenage musicians.
Other sessions have been led by Jake Bugg and Emeli Sande.
The audience of 12- to 16-year-olds are treated to a private performance of First Aid Kit hits: Waitress Song, Wolf, their cover of Simon and Garfunkel's Bridge over Troubled Water - and finally Emmylou.
"I wrote my first song when I was six," Klara tells the audience.
"Music has always been part of our lives but we never went to music school."
The girls were born into a musical family. Their talk includes references to their earliest influences, ranging from their father's time in a Swedish rock pop band to listening to the Spice Girls and the Back Street Boys.
'Kind of geeks'
By their early teens, they had moved on to less typical idols for their age group: Bright Eyes, Bob Dylan, Leonard Cohen, Joni Mitchell, Gram Parsons and The Carter Family.
"We became more kind of geeks," says Klara.
Klara taught herself to play the guitar and Johanna learned to play keyboard.
"We don't know any music theory - well, maybe a little bit."
Now they say they know each other so well they "hardly have to think" about how their voices work together when singing different harmonies.
Their global break came with a cover of Fleet Foxes' Tiger Mountain Peasant Song, which the American band shared online.
"They put our cover on their page," says Johanna.
"It got half a million views really quickly".
Soon afterwards, they began touring internationally and left school aged 16 and 18.
"We made our first like real album five years ago and have never gone back."
Johanna reveals she once applied for Pop Idol "and I didn't get in, but now I have my revenge!"
The question-and-answer session reveals their teenage crushes and the meaning of their matching tattoos.
"It's a native American sign for protection. It's a sisterhood thing.
"We travel around a lot, and it can be scary playing these big stages - but having your sister there means you feel more at home," says Klara.
"We still fight, especially about we wear on stage," adds Johanna.
The girl-only workshop is a hit with the participants.
"There's less pressure than if there had been boys here. We can do what they do," says 16-year-old Rhiannon.
"It's more comfortable. You don't feel as self-conscious," adds Lanta, 15.
The fact the band are largely self-taught also generates interest.
"I am awful at music theory too," says Rhiannon.
"I liked that they auditioned for Pop Idol and didn't get in," says Joy.
"Their voices work so well together, and I love their passion for music," says Sarah.
After a short break it's time for a harmony workshop, a chance to learn the parts of Emmylou and a joint performance.
The sisters teach the students the voice exercises they learned after Johanna lost her voice and missed two performances.
"The girl who taught us this said not to do it in front of anyone you are in love with. You stick your tongue behind your teeth and then push it out.
"Come on guys you've got to do this.
"It stretches your tongue and your throat."
The students are split into two groups, one to learn the melody of Emmylou, the other the harmony.
At first the students are soft and shy - but by the end of the workshop they are singing strongly.
"This sounds great," says Klara.
"I want them to come on stage with us and join our tour."