Ani DiFranco, Union Chapel, London

“I feel very hopeful for 2012, so thank you to the Occupiers,” maintains Ani DiFranco. “All working people are Occupiers, too… occupying this planet,” she adds.

The outspoken feminist folkie from Buffalo, New York, has always been on the side of the angels and her congregation here at Union Chapel simply adore her for it; there was a huge queue, snaking around the corner, for this gig well over two hours before it began. After the workers’ anthem “¿Which Side Are You On?”, off her new album of the same name, a particularly avid fan purposely moves towards the stage and places down some underwear. The 41-year-old singer-songwriter simply cannot put a foot wrong tonight – even her hastily composed “spiritual poem”, delivered mid-set, about streams, patriarchal visions and “fundamental disparity” garners huge whoops.

There’s a worrying scarcity of protest singers around at the moment – which is particularly troubling given our straightened times – so it’s refreshing that there are still musicians out there gravely wailing against injustice. Twenty albums down the line – all released on her own independent label, Righteous Babe Records – and the diminutive singer is still cross (although she’s rather cheerful here) about quite a few things, including sexism, sexual abuse, political corruption and the environment, topics all touched upon at this reverential concert.

She first came to prominence in the early 1990s at the same time as Edie Brickell, Tori Amos and Natalie Merchant, but DiFranco is an angrier, less whimsical beast. Never a massively commercial success, DiFranco has always been admired for her distinctive staccato, hurried fingerpicking style and nifty lyricism. And she delivers an intoxicating solo (bar a couple of numbers) performance with an array of guitars tonight. She tears through a lot of material from her new record, including a rather lovely “unloved happier” track, which didn’t make it on to ¿Which Side Are You On?. Songs that did make the cut – “J” and “Mariachi” – receive an airing and both jazz-infused numbers sound reminiscent of material from Joni Mitchell’s The Hissing of Summer Lawns. “Life Boat” is a more haunting character study, which focuses on a damaged woman from New Orleans (DiFranco’s home for the past eight years) with her “tired old face, still grinning most of the time”.

However, the loudest cheers – and they are loud – are reserved for old favourites such “Little Plastic Castle”, “Swan Dive and “As Is”. This very adept performer receives a long ovation, before robustly bowing out on the excellent “Both Hands” and “32 Flavours”.