He tells Music Radar: "I think a lot of it has to do with the fact we're both very blues orientated artists - we draw from a certain amount of soul in the way we approach things. I think that's where our chemistry really lies - I don't think we've ever really had an argument.

"There have certainly been times when there might be a part of a lyric or an idea where it's a case of, 'I'm not sure about that' or, 'I'm coming up with something like this, I'm not reacting to it.' The cool thing about that is we've both been in this dog and pony show long enough to know what's going to happen.