The timing of the met isn't perfect. In the polyrhythm mode, the downbeats will "tear" from beat to beat, only occasionally lining up perfectly to make a "double stop" sound. This means the integrity of any polyrhythm this app creates is corrupted. In all, this renders the app not useful for situations like marching percussion, which require extreme rhythmic accuracy in complex rhythms. This is a disappointing discovery as I have just wasted my money.