It's the tail end of a long rehearsal when I walk in to the room. Under normal circumstances, energy levels would be flagging, but not with Lucy Schaufer around. 'I want this to sound like the swish of a southern lady's tail, y'know what I'm saying?' She drawls in her heavy American accent, with just the slightest swing of her hips.

The piece in question is 'The Best Thing of All', one of the songs on the soprano's new CD, 'Carpentersville'. And it's no wonder the mezzo-soprano feels so strongly about it. Because 'Carpentersville', named after the American town north-west of Chicago where she grew up, is a very personal enterprise. It began to take shape after November 2010, the month that Schaufer's father died. 'You take stock of your life when both your parents are gone,' says Schaufer, 'and you think what makes me happy? And what makes me, me?'

The answers to both questions lie in the CD's contents. Filled almost to the brim with American composers such as Leonard Bernstein, Stewart Wallace and Adam Guettel, it's something of a 'coming home' for Schaufer, who now lives in England with her English tenor husband Christopher Gillett. But it's also an exercise in miscellany, combining opera, music theatre, contemporary classical music and even part of Bach's St Matthew Passion.

And that's to be expected of Schaufer, whose eclectic singing credits range from Clare de Loone in the ENO's production of Bernstein's musical On the Town, to Jennie the dog in Oliver Knussen's contemporary opera Higglety Pigglety Pop!, presented as part of Knussen's birthday celebrations at last year's Aldeburgh Festival. Equally comfortable with these different genres and disciplines, she occupies an undefinable space in the 'who's who' of classical music. 'In a funny sort of way, Schaufer's versatility compromises her as an artist because the opera world doesn't quite know how to categorise her', says Matthew Freeman, who produced the CD, 'so she probably hasn't had quite the profile that she deserves'.

What unifies Schaufer's career, Freeman says, is her 'phenomenal' ability to communicate. As far as she is concerned, singing is about storytelling, and each track on 'Carpentersville' has its own tale to tell. Many of the songs, such as 'Margaret', speak of motherhood, 'and as a stepmother, that's a strong part of who I am', she says. The excerpt from Bach's St Matthew Passion, and in particular the image of somebody weeping at Christ's feet, has an even more emotive resonance for Schaufer. As her father's hospice nurse until his death, she can relate to the experience of 'watching somebody die, hoping against all hope that you didn't cause them any pain.' It was that sense of grief and helplessness that she wanted to honour in her rendition of the piece.

With such an emotionally and stylistically varied programme to tackle, the main challenge, as Freeman points out, was to structure the recording sessions 'such that Lucy's head as well as her voice was in the right place at the right time.' Another was to ensure that she was left with reserves at the end of a three-day recording, because the thing about Schaufer, is that 'she embraces everything at 100 miles per hour.'

But when I quiz Schaufer herself about the recording's emotional and physical demands, her answer is matter of fact: 'It's my job. And I don't want to ever say that I played something safe.'