Game music that responds to your actions can be a magical thing. I'm talking about sneaking through enemy lines accompanied by an eerie string quartet, or cresting a hill while the scenery and music swell around you. Joost van Dongen, the man behind Proun and Cello Fortress, recently did an experiment with live soundtrack improvisation that makes for interesting reading.
Dongen and his fellow improviser Rene Derks set up shop at the Abunai convention in the Netherlands and invited people to come in and play any of 40 games. After turning in-game soundtracks off, Dongen with his cello and Derks on a djembe drum improvised their own music in response to whatever was happening on-screen.
In his blog post, Joost is keen to stress that it didn't always work: "As always with improvisation, some of it sounds bad, a lot sounds okay, and some moments are pure magic that can only be experienced there and then." He goes into much greater detail about what worked, what didn't, and why than I will here, but if you don't have the time to read the full post I'll run you through the highlights.
Limbo was one of their most successful performances, which Joost attributes to the game's "slow pace with a strong emotional arc". It's easy to see how having a cellist playing shrieking notes from just behind you as you get impaled on a spider could add to the experience. Or kill you.
They also found success with The Binding of Issac, with Rene building on a simple that he expanded as the player explored each floor. Joost held back, only playing a short melody when a chest got opened or the player cleared a room, but started playing properly when the player reached a boss. Perhaps unsurprisingly, the duo found they struggled with fast paced games, with one street fighter providing an impressive display of skill but leaving the musicians struggling to keep up.
It's worth reading Joost's own summary of the experiment, which you can do right here.
This isn't the first time Joost has incorporated live music into games. His game Cello Fortress tasks one actual real life cellist with protecting a fortress from four invaders that use more conventional controls, making it the most fascinating game I'll never get to play.