Brian Eno, ambient music master, has teamed up with musician/programmer Peter Chilvers to put together one of the coolest and most unique iPhone apps to hit the App Store yet.

Called Bloom, it’s “part instrument, part composition and part artwork.” It’s a must-have for those who enjoy music and prize creativity.

Unlike most music-creation apps, it doesn’t take an existing musical instrument and shove it awkwardly into the iPhone’s UI. Instead, it creates a completely new musical instrument designed specifically for the iPhone and its interface. To put it simply, you’re provided with a colored screen and a quiet drone. As you tap the screen in various places, different tones play depending on where you tapped the screen. They then loop, creating a unique piece of music on the fly, one that changes gradually on its own, swirling and slowing down once you stop tapping.

You can also just let it create music by itself, coming up with a completely new piece every time you run it. It’s also beautiful, with the tones appearing as colored spots that slowly fade. It’s as satisfying to actively play with as it is to let do its own thing, if you just want to relax and listen.

Bloom is available for download at the App Store for $3.99.