I’m a guitar player, and I use tablature notation editors such as Guitar Pro a lot. However, it gets complicated fast when I write polyrhythmic/polymetric drum parts, because shifts tend to go over the bar lines and it’s hard to make sense it’s correct visually (may be even harder if you listen to it). The other property of such parts is: it tends to unfold from simple ideas such as “I want to create a drum part that will have a 3 against 4 feel with a kick drum against a snare drum”. The other way to think about it is that it has a simple blueprint, but it’s tricky and error-prone to express in Western musical notation. This is why Polyrhythmix exists. I wanted to have a simple tool to workshop/brainstorm rhythmic ideas and evaluate them by having a MIDI playback. I’m into modern Progressive Rock/Metal music, Fusion, so it all applies very well. I have an impression it may be useful for Indian Carnatic music as well, but I would like to get some insightful confirmation on that.