It's a fitting portrait. Adu's music is cryptic, edgy, oscillating between serious commentary and flippant experimentation. Her latest album, Dark Joan, is a take on the story of Joan of Arc, who led France to victory in the Hundred Years War through what she described as divine guidance.

There's little in terms of divinity in Adu's title track but it opens with aggressive offence: "Didn't you think I would come back for you all," she sings, to a stormy assault of keys.

She said: "Dark Joan is a tale about an urban Joan of Arc.

"I was living in Brixton at the time when I wrote this song. The inspiration of this song was the popular image of Joan d'Arc superimposed on contemporary urban London.

"However, it isn't a literal representation of her life in any way. The song also has images of strength and battle, both male and female, through art and other means. The end of the song is calls on our internal super-powers of compassion to battle the materialistic energy of these times."

She sings: "Lord why show me angels as a child / Then grow up and make me someone mild? / I can't help you all but I'll do my best / All the shining knights are having a rest."

"I'm tired of looking around and seeing what is around here," Adu says, admitting that her bemusement concerns the frightening abundance of celebrity magazines in a materially-driven society.

The premise is echoed throughout much of the album: "It's about being grateful in these materially-driven times," she says.

That is reflected in the line "No time to waste in your potential in the malls."

She extends her attack on consumerism to the sensation-seeking aspect of British media, referring to its obsession with celebrity drug habits,

"I would be more interested if they wrote about him making home-made cookies, for example," she said, referring to Pete Doherty's well-documented drug habit, "The media make meat out of everyone. He's just a nice sensitive, artistic young guy."

And she would know, she travelled to Moscow with Doherty with the British Council as part of an exchange programme.

This week, Adu brings her broad-ranging folk-pop to Sheffield as part of a UK tour with fellow FRIZZ record artist Art Terry. The tour also celebrates the release of Dark Joan, her first official international release.

"All my other records have been self-released," she says.

The album's hard to categorise but whets every appetite from brooding pop to abstract electro. Songs sway between lo-fo slow trip hop with electronica undertones – as in the mellow track Answerphone – and rich piano-led melodies.

Such contrast reflects Adu's musical background – the London-born, New Zealand-bred singer songwriter has appeared with the New Zealand Symphony Orchestra and is in the process of composing an electronic arrangement for a chamber group.