From within a jungle of musical instruments and audio cables, a voice flows like nectar: British singer PJ Harvey recording her ninth studio album in front of an audience hidden by a one-way mirror.
The slender 45-year-old rocker, wearing headphones and black trouser suit, is surrounded by musicians and her longstanding producer Flood, an industry heavyweight who has worked with Nick Cave, Nine Inch Nails and U2.
"And one, two, three, four," she counts in the group before attempting yet another version of a track from her new album, the first since 2011's "Let England Shake".
The box-shaped studio is designed to accomodate an audience, and is built inside the neo-classical arts centre of Somerset House on the bank of London's River Thames.
"I was looking for a space to record in London and knew I didn't want it to be a conventional recording studio," the singer said in an interview for a handbook that accompanies the "Recording in Progress" project, a collaboration with artistic production company Artangel.
Harvey explained that her songs often take on the atmosphere of the recording space, and the "resonance" of Somerset House -- originally a Tudor palace that later housed the Royal Navy command and tax office -- chimes with some of the album's historical themes.
- 'Sculpting in sound' -
The public can attend the recording sessions in groups of 40, entering a lower level adorned with white sheets on which the singer has scrawled the lyrics of her album in black ink.
The recording studio is an enclosed white box, with one-way glass allowing the public to witness the creative process while remaining invisible to the musicians, transforming the recording process into "sculpting in sound," Harvey said.
The award-winning musician had once hoped to become a visual artist -- she gave up the chance to study sculpture at London's Central St. Martins art college to record her acclaimed 1992 debut album "Dry" -- and visual art remains a "prime inspiration".
"I want it to operate as if we're an exhibition in an art gallery," Harvey said. "I like the idea of the vitrine, that you're looking into a glass display case at a record being made."
Surrounded by myriad instruments ranging from an electric guitar to a melodica, a harmonica and acoustic keyboard, producer Flood guides the musicians as they play and replay songs, polishing them to perfection.
"That one was really good," Flood says, before prompting a few minutes later: "Let's try one more."
The musicians react to his instructions and occasionally improvise, as a sound engineer wearing a Manchester United football top works on a mixing console.
- 'Part of the recording' -
The architectural installation lays bare the process of making an album. During one song, "Ministry of Social Affairs", Harvey stops to ask a musician to change a part played on an electric piano.
"I like it when you play..." she begins, before singing a series of notes. "But I don't like the other two beats."
The musician makes a change and the work continues.
The public can also witness moments of laughter between the musicians and the small quirks of the recording process, such as when the amplifiers suddenly refuse to work.
Harvey remains deeply focused as she tries different takes, sings, and plays the electric guitar or saxophone, witnessed by an audience she cannot see or hear, but which is thrilled whenever her voice echoes out into the gallery.
"Because I'm a musician myself I thought I'd be a bit like an intruder violating someone's vulnerable space," said 22-year old audience member Gigi Birch as she left Somerset House. "I was transfixed."
"It's amazing because it's someone I've known for so long. I can't believe how small she is. She's so tiny... how can such a massive voice come out of someone so tiny. She's superb, she's just majestic really."
The experience makes the audience "a little bit part of the recording," Birch added.
Assuming the public sessions finish as planned in mid-February, the album will be released in early 2016.