With almost 20 albums under her belt, and credits for arranging and playing every instrument on her last three albums - records which have again marked her out as a musician with a talent for reinvention - it's a pretty big deal to have her playing at The Hexagon on Thursday.
The Guide spoke to Joan back in September, after her latest, jazz-infused album, Starlight, had hit the shops, to find out what the woman behind hits including Love and Affection, Willow and Me Myself I has in store for us. The first question was one that many musicians would love to know the answer to - what is the secret to her enduring, 40-year-long career?
"I have no idea!" said Joan. "You have to ask other people that one. I like to keep myself interested, I think part of my strength is also my weakness - I do move about quite a bit. I don't write a song to be a hit. I do not think about that - of course I do want it to be a hit but I can write really well and write a lot and move about a bit, but because I move about so much people cannot settle on what they think of me - they think, 'she's rock, no she's blues, no she's jazz'. At the moment, it's something people like. They like the surprise as much as I like the surprises!"
She added that having control over her music, and being able to reinvent herself, was important to her. "It's a nice thing to be able to do it," she said of Starlight's blues stylings. "It does keep me fresh and it's a nice thing to think: 'I want to do this' and then do it, and then set myself a task of writing an album of jazz songs. It gives me a challenge and it just sounded like a nice thing to do. With this album, probably, I have changed quite quickly, I think it has taken people by surprise!
"I have always played my instruments for myself, to me it's not so new; to everyone else it's new! In 2003, I decided it was time to do it on record. I have always arranged my songs - even on my early songs, my name's not down as the person who arranged it, but it was me! When you're in the studio someone has to know how the song is going - I feel I should be that person."
Joan explained that her lyrics had always been essentially grounded in relationships.
"It's always been the case. Whenever anyone talks about being here, what they are talking about is always in relationship to a person. Whatever you talk about you have to relate it to a person - that's when it comes alive. We are here to communicate with each other.
"It's from people I have seen, people I know, people I do not know, on the tv, in newspapers, things I have read. I need to write in that personal way.
"It's funny, someone was saying they had written a song a while ago that had nothing to do with them and then they played it and something had happened to them and you get caught up in that moment. But something might happen years down the road that really makes you connect with that song. That's certainly happened to me. I can connect to those songs. Partly because I have written them, and partly because you see the audience reacting to them."
Joan added that picking songs to play at any given show could be a bit of a headache: "In terms of getting songs for the setlists, that's super, super hard - I cannot tell you how hard that is. This imet I have five setlists I'm working from. Two of them are shows that are an hour 50 mins long and another one is an hour and another one is half an hour. It's really hard because I cannot put everything I have recorded into three hours! It's very, very difficult to know which songs to play, for the audience, and then the band says, 'why are you not playing that one I love that one!!'"
Joan will be supported at The Hexagon by Chris Wood, and also London's Worry Dolls, who play country-tinged folk. The band were one of 56 acts chosen as part of Armatrading's Local Talent initiative. Tickets cost £29.50 from www.readingarts.com or call 0118 960 6060.