Try ~crappy~ regular headset microphone and/or whistling for some basic edge cases :D

It worked quite well to start with, but then after a few bars deteriorated to mostly outputting pauses, and a stream of short notes (without pauses) when singing legato. Could be due to the aforementioned microphone, or is there some internal state that does not get cleared up when one clears up the score? I tried twiddling some of the variables that seemed related, but no noticeable improvement.