No matter how talented they are, female singers - especially black American female soloists - are often under pressure to portray a sexy, booty-based vision of feminity. Last night, with a performance that was as emotionally moving as it was technically brilliant, India Arie was having none of it.

Dressed in casual clothes that were clearly designed for comfort rather than titillation, she launched into her current single, I Am Not My Hair, showing off her exquisite alto and understated vibe as her heartfelt lyrics bemoaned the way in which black women are judged on their hairstyles.

A backing band composed entirely of highly accomplished musicians, including a double-bass player and two breathtaking backing singers, created an epic, atmospheric opening that had the crowd screaming.

Like her 2001 hit Brown Skin, which celebrates the physical beauty of an African American lover, I Am Not My Hair, contains an assertive Afrocentric edge, tinged with feminism. But Arie's feminism is not anti-men, and nor is her Afrocentricity an expression of resentment towards white people.

Arie's positive-minded benevolence transcended these narrow boundaries with ease. I could almost hear the sound of a couple of thousand eyebrows being raised at the distinctively country and western-style intro of Summer, a new album track on which she duets with Gary Levox, lead singer of huge contemporary country group Rascal Flatts. But the song worked, her deep, rich voice wrapping itself round the hillbilly chords as naturally as it had overlaid the soul and funk flavour that characterised the rest of the night.

Her cover of Cyndi Lauper's True Colours injected not only soul, but also new harmonies and melodic complexity into the song, earning a rapturous response.

Arie's appeal was summed up when she introduced These Eyes. "There are so many songs about the extremes of love and hate in a relationship, but this is about the grey area that no one ever sings about," she explained, before delivering a beautifully meditative track embodying stunning strength of feeling.

In an age where extremes of all kinds can seem like essential components of success, India Arie provided refreshing proof that subtlety, integrity and sensitivity can still sell.