Probably my most important musical revelation in recent years has been the voice of Mary Gauthier. She claims Woody Guthrie, Hank Williams and Bob Dylan as influences, but her songs offer a unique vision of the world, with a voice to match that carries an immediate stamp of truth.

In the title track of her 2005 album Mercy Now she describes the human race as hanging “in the balance between Hell and hallowed ground”, or, as her next album title puts it, between daylight and dark. Only the hand of grace, the song tells us, can save us. The desire for that grace runs through all of Gauthier’s work, but in her songs this grace is extended for the most part to a host of beautiful misfits and malcontents. The title track of an earlier album, Drag Queens in Limousines, sings the praises of outcasts who took her in when no-one else would, and they reappear in Wheel inside the Wheel, her astonishing send-off for a dead musician friend. The song describes a Mardi Gras parade of souls across the sky, and the chorus evokes Ezekiel as well as Blake: “Souls ain’t born, souls don’t die / Soul ain’t made of earth, ain’t made of water, ain’t made of sky / So, ride that flaming circle, wind that golden reel / And roll on, brother, in the wheel inside the wheel …”, but the invitation list pairs the voodoo priestess Marie Laveau with Oscar Wilde, and the song builds up to the unforgettable couplet: “… The French Quarter queens in their high-heeled disguise / Sing “Over the Rainbow” till Judy Garland quivers and sighs …”

Most often Gauthier’s songs seek out dark places and characters that are in some way bereft, and then imbue them with dignity and courage. So, for instance, Between Daylight and Dark ends with a song entitled Thanksgiving, in which the main character and her grandmother visit one of the inmates of Tallula State Prison. The grandmother’s hands tremble as she is frisked by the guards, but afterwards “she wipes their touch off her dress, stands tall and heads in.” It is the way Gauthier sings these lines as much as the power inherent in the words that makes the song so moving.

At other times the songs contain the possibility of redemption, but at an immense cost. So, for instance, in Before You Leave, a lover addresses a beloved who is leaving, clearly for good: “The darkness that shadowed you was mine, it was never yours at all / And the light behind your eyes that used to shine gets brighter as you walk away …” Again, it is the voice that breaks your heart as much as the words it phrases, though as I write this the words themselves are enough.

And so I could go on. The other night a good friend of mine brought me a rare EP Gauthier recorded at about the same time as Mercy Now. It contains yet another heartbreaking song called Christmas in Paradise about a woman living under the Cow Key Bridge with her friend Davey. It is Christmas time, and Davey has obligingly stolen a Christmas tree and tied it to the bridge. The song ends with the radio playing Christmas music as the two of them get high together, while Davey shouts “Merry Christmas, y’all” to the cars passing by. The character in the song is sentimental, but Gauthier is not. Christmas in paradise indeed.

Again and again Gauthier shines the light of her acute understanding and considerable compassion into dark, forgotten places and makes us feel at home there. She has that rare, dangerous curiosity about how other people live, about what goes on behind bars, under bridges. It is this combination that earns her a place alongside the greatest songwriters, and gives me hope for the future of songwriting.