How We Made Heavy River:

These tracks - like all the best ideas - turned up out of the blue.

It actually started with the photograph of the drum kit looking over the Thames (taken on a bitterly cold day in April). Then I remembered that John had sent me a 45-second-long electronic noodle a couple of weeks earlier.

It's nice, I thought, but it needs to be much longer and in a lower register to leave some time and space for guitar.

So, like George Martin matching up John and Paul's contributions to A Day in the Life, I clicked a button on Ableton, dropping it two octaves and making it four times longer. But it also gave it a shimmering judder which made me think of the river...

In the spirit of free jazz I then improvised a guitar part over the top of it (one take, naturally) and we set to, mixing different versions, trying out increasingly far out audio FX.

Eventually we reached a point where it was almost unrecognisable (a point we were happy with), and we had four connected ambient pieces that we liked a lot.

And then we thought about the drum kit...

So we added illy B's Secret Bearer to the mix...

And the resulting mashup is one of the heaviest, funkiest tracks we've made.