When reading a MidiMix, if an instrument can't be retrieved, we use the "best" GM instrument instead. But nothing specific is done when it's an instrument for a drums channel, so we end up having a Piano on a drums channel. This can generate various issues.
When reading a MidiMix, if an instrument can't be retrieved, we use the "best" GM instrument instead. But nothing specific is done when it's an instrument for a drums channel, so we end up having a Piano on a drums channel. This can generate various issues.