"With all of the songs I create this little film in my head, mostly in woodland, or on hills, or mountains. A friend asked me the other day, 'Do you dream in the third person?' Well, when I'm writing songs, I can be cast in the third or first person, but I'll see an event happening over there and cast myself in that role, perhaps…"
Released this week, White Chalk is PJ's eighth studio album to date and her first new material since 2004's critically acclaimed Uh Huh Her.
"I say I don't want to retread old ground and sometimes I achieve that and other times I don't, but it's always what I strive for. And I was particularly vigilant with this record. I think I did a better job than I have done for quite a few years – it did see through my initial idea. It's too easy to get distracted, or fall in love with a song, even if it's very much like what you've done before. This time around, it was to do with the plethora of music around us now and I don't want to add anything that's not new, there seems so little point because there is so much of everything. That's what made me pursue the piano route."
The album's first track, The Devil, proved difficult to lay down in the recording studio.
"It's almost laughable, for five months we were recording the album and that song, The Devil, would not be recorded, it would not be had. We couldn't get it," recalls PJ. "And, this is technical, but I was hearing the song in three, like a waltz, and (co-producers] Flood and John Parish were hearing it in 4/4, completely on the beat. And we couldn't marry the two at all.
"And we were arguing and swearing at each other for months and months. So in the end we took away the rhythm, so there isn't a specified rhythm.
"But because I still hear it as a waltz, my left hand is the only anchor and my right hand can meander – so I have to use the metronome so that my right hand doesn't go right out of time. It's to hammer into me the way everyone other than myself hears the song. I've grown to quite like the metronome now, especially being such a terrible player. I use it in practice."
"The great thing about learning a new instrument from scratch is that it enables you to be more childlike, more unaffected by adulthood. When that intellectual knowledge is stripped away from you, it liberates your imagination. I don't know how to play the piano, I'm very hamfisted at it, and I love that. In the future, I'd quite like to keep grabbing at instruments I've never played before. It forces me into the position of listening for the first time and I find that very freeing."
PJ insists she feels most at home in the live arena.
"I don't feel that I'm 'not myself', that I'm not Polly at any time when I'm on stage. I really enjoy singing and playing songs. I'd be doing so whether people were watching or not. It's something that I want, need and have to do. So I feel very myself singing and playing… when I'm singing any given song. I'm absolutely inside it. But then, when I stop singing and step out of it, I step out and it's like, OK, I'm here with these nice people and I'm going to talk to them.
"I read this lovely quote by Dylan the other day. He said that all you have to do with songs is just to let them be there, in the room. And I love that, because it's exactly how I feel. In some ways, the songs are nothing to do with me and yet the come through me. I'm the conduit for them."
PJ sees herself as a songwriter and not a musician: "It occurred to me the other day, I am a songwriter. I'm not a musician in that I won't touch an instrument from one year to the next unless I'm performing or recording. It all goes on in here, in my brain. I write the songs in my brain and then come to the instruments at the last minute. This goes for the guitar as well. I had to practice hard for a month just to learn to play guitar again. My fingers were blistered."
She adds: "I feel much more like an explorer. I'm much more excited about laying my hands on anything that's new and that I don't understand. That's what's most interesting to me at the moment. It's a life's work, exploring. I sometimes wake up in a panic, thinking I'll never get to explore all these ideas I want to try before I die. It's a lovely but scary feeling."
* PJ Harvey's new album, White Chalk, is out now on the Universal Island Records label.