Preview: The Eden Sessions, Eden Project, Cornwall

The Magic Numbers will play at the Eden Project, with José Gonzalez in support, on 12 August as part of a series of concerts including performances by Muse, Goldfrapp and Snow Patrol. The melodic quartet - made up of two pairs of siblings, Romeo and Michele Stodart, and Sean and Angela Gannon - are currently in a London recording studio, putting the final touches to their as yet untitled second album.

Last year the band had three Top 20 singles, were nominated for the Mercury Music Prize and played with Brian Wilson. Since then, their debut album has gone platinum, while their latest single "I See You, You See Me"hit the Top 30 this year.

Romeo, the singer/songwriter and guitarist, says he writes best about broken relationships. "['I See You, You See Me'] was written at my mum and dad's west London house in Hanwell," he says. "They have been happily married for 30 years, but they were having a big argument, as couples do. I wrote it as a duet in the morning and we played it that night. I wanted to write a duet that wasn't cheesy. I am very proud of it." This song was a particularly quick concoction for Romeo. "Three years before the album was even out, I was imagining that song on it."

Was success a shock? "Everything came at once, but we built it up organically." Is it hard being in a band with family? "Extremely difficult at times. We have a lot of fun, as well as fights. The good thing is that I finally have somebody in the band who totally understands me. The key thing, for the four of us, is to be ourselves. With other people you hold back. It helps our music."

The Eden Project opened in March 2001 and is home to the world's biggest greenhouse, which has its own microclimate. This will provide a backdrop to the Eden Sessions, which in the past have featured Moby, Brian Wilson, Pulp and Keane. Last year the Eden Project hosted Live8 - Africa Calling.

The Eden Sessions, 12-27 August (01726 811972, www.edenbookings.com)