Music review: Anais Mitchell & Jefferson Hamer, Cecil Sharp House, London

Having impressed with her folk-opera Hadestown (with Justin Vernon and Ani de Franco), and followed up with a winning solo album, Young Man in America, Anais Mitchell began 2013 with a new project: the Child Ballads.

New for her and her recording partner Jefferson Hamer, although hardly new for the folk world; over 300 English and Scottish folks songs were collected by Francis James Child in the late nineteenth century, though their provenance is much older.

It's apt, then, that they’re playing at Cecil Sharp House, home to the English Folk Dance and Song Society, in a wood-panelled room that the cutely psyched Mitchell describes as “the spiritual home for this music.” There's a mixed audience of all ages except, well children – the Child Ballads aren't exactly aimed at kids, being full of illegitimate pregnancies, drowning lovers and hanged husbands.

With an acoustic guitar a-piece, they play all seven ballads from the record. Opener 'Sir Patrick Spens' sets the tone: there's soft, delicate dual finger-picking, and while the tang of her voice dominates, his higher harmonies are very sweet. It tells of a ship-wreck; they strum at more dramatic moments, illustrating the ship's moan.

'Riddles Wisely Expounded' has a jog-trot rhythm, and is prettily repetitive in phrasing both lyrical and musical - “Lay the bend to the bonny broom... and you'll beguile the lady soon”. It is beguiling, certainly, though even better is 'Willie's Lady', with intimate harmonies and dark, fluttering guitar. And when they explain the plot – it's about a cursed, never-ending pregnancy - it's coyly, cheerfully revealed that our leading lady, too, is with child.

Both young, sparky Americans, Mitchell and Hamer could look at first glance like trendy folk-pop adopters - he's in tight trousers, she a tight skirt – but there's great respect for tradition here, alongside a lightness of touch confirming these tunes can take a little playing around with. The crowd loves it, even readily forgiving them for “eviscerating the fairies” from their trimmed version of 'Tam Lin'.

It's not all ballads – they do stripped down solo material, as well as covers of Woody Guthrie's 'Pastures of Plenty', Emmylou Harris and Gram Parsons' 'Hearts on Fire', and even a daffy but adorable, laughter-filled version of Jethro Tull's 'Skating Away on the Thin Ice of the New Day'. The last two are played unplugged, and they step down from the stage almost into the audience, storytellers for the people to the last.