WHAT began as a friendship when The Staves toured with Bon Iver has turned into the Hertfordshire sisters’ second album, If I Was.

Although the release has been put back from this week to March 23 on the Atlantic Records label, harmony-singing Watford siblings Emily, Jessica and Camilla Staveley-Taylor are nevertheless heading out on a tour this week that will showcase the fruits of their recording sessions with Bon Iver’s Justin Vernon at April Base, his studios in Eau Claire, Wisconsin.

“We’d become friends with Justin and his band on tour and he just invited us to go and hang out there, no pressure to make any music,” recalls Jessica. “But as soon as we got there, it was a combination of the environment, the studio, and everything aligned to make it the perfect place for us, as we had this pent-up writing in us after two years of touring.

“So it was a bit of an outpouring that caught us by surprise as we did ten songs. We didn’t go back for another four months, but by the end of that, when we were still doing more demos, we thought, ‘what are we doing? Are we making an album or not?’, and Justin said he was totally up for making an album.”

The album sleeve captures the recording atmosphere perfectly, as the sisters walk away from Vernon’s Polaroid camera through a snowy woodland clearing. “His studio is in a really isolated place, really good for focusing on music, and the album definitely wouldn’t have turned out the way it did without Julian.” says Jessica.

“He took that photo in a lovely avenue with all those trees and he said it looked really cool with us walking through it. ‘Stand there for a photo,’ he said.

“I think it was on the last day of recording too, so it was perfect.”

Jessica recalls the creative process that took the initial blueprint of 2012’s Dead & Born & Grown debut album and gave it more darkness and depth. “We never dried up creatively, though there were some moments of difficulty, perfecting things,” she says.

“It felt like a second coming, almost like making a first record again, though we do still connect with our debut, which was made in London and was a collection of our songs,spanning our really early songs to songs we wrote in the studio. Whereas the second album was more focused, written across two years rather than a lifetime. It feels more relevant somehow.”

Given that If I Was was scheduled originally for release last September, the Staveley-Taylor sisters are definitely ready to launch it.

“The title If I Was is a Iyric from the opening song, Blood I Bled, a song about making choices. Like in the sleeve photo of us walking away, it summed up how this album felt like moving forward and walking away from things in the past,” says Jessica. “It’s a feeling of re-birth and starting again.”

This is the moment for The Staves, even if Jessica does not feel part of a rise in British harmony singing that is bringing Ward Thomas and The Shires to prominence.

“I don’t see a huge amount of harmony singing out there, but I’ve always sung in harmony with my sisters, being influenced by Crosby, Stills, Nash and Young and The Beatles.

I remember my parents listening to The Beatles, Eagles, Simon & Garfunkel, even Abba, and I remember feeling rather alone until hearing the Fleet Foxes and being so impressed by what those guys were doing,” she says.

“That really kicked the door open; you heard that music on the radio for the first time, though I felt it had died down again, even though Mumford & Sons have sung harmonies and done incredibly well.

“It’s great that there are now English sisters doing it and Swedish sisters [First Aid Kit] doing it and that it’s no longer seen as old music.”

• The Staves play Leeds City Varieties Music Hall tonight, 7.30pm, and Pocklington Arts Centre on Monday, 8pm, supported by Flo Morrissey. Box office: Leeds, 0113 243 0808 or cityvarieties.co.uk; Pocklington, 01759 301547 or pocklingtonartscentre.co.uk