Welcome to the ninth episode of Signal Chain. This pop-up newsletter is a creative collaboration between generative musician Duncan Geere and photographer Oliver Holms.

We’re taking turns to send new work to each other. Each new piece is inspired by the piece before. We’re building a chain of influence together and you’re along for the ride. New installments are released on the 1st and 15th of every month, and you can unsubscribe at any time using the link in the footer.

Hi Oliver,

This is it - my last composition of the first season of Signal Chain. I've enormously enjoyed creating each one of the five tracks that I've shared throughout this season, but this one in particular has been my favourite of all.

I think it's customary by now for me to start each message with "I loved your photo" but it's true, and I loved the story behind it too (your poor dog). I'm a bit of an atmospheric optics nerd, and the rainbow is just the tip of the iceberg - I still vividly recall the day I first saw a circumzenithal arc, in a place I never normally look - directly above my head. I dream of one day seeing a complete display - though it's pretty difficult to do so without living in a ski resort or Antarctica.

I'm supposed to be talking about this new track, though, so let's get into that. Inspired by the seven colours of the rainbow, I ran a very slow sawtooth LFO through a VCA and a quantizer set to the mixolydian mode to get a simple seven note sequence, which is where the track begins. Bright and simple.

But real-world rainbows don't stay constant - they fade in and out, sometimes stronger, sometimes weaker, so I tried to replicate that with the rest of my toolkit. I used granulation from the appropriately-titled Monsoon, a background drone from the Ensemble Oscillator, and the Fall script from Norns on the second half of the track.

The intended result is a sonification of the experience of watching a rainbow slowly fade away. I hope you like it.

Click the player to listen to the track.

If you can’t see the player, then make sure you’ve got images enabled or just click this link.

That's it from me. Over to you for the final entry in season one of Signal Chain.

- Duncan