Looks like thumbs in general are a real issue for me.
I'm teaching myself the recorder, and would not want to acquire a bad habit. I'm approaching notes in the higher octave (soprano recorder) and closing the thumb hole partially in a solid way becomes of paramount importance.
My question is what to do with the thumb when playing notes that don't require the thumb (e.g. high D). I find myself starting a piece with my thumb well in position (upper left part of my thumb closes the thumb hole), which allows me to play high notes that require the thumb hole to be half closed (e.g. high E, G, A) very swiftly (I just gently slide my thumb back), but if after a while I encounter the aforementioned high D then it becomes very hard to find that good thumb position again while playing.
So what does one do when one plays a high D? Does one simply slide it more and more (like one would do for partially closed notes) but keeping it on the recorder or does one lift it completely from the instrument? I have tried the former solution and the issue seems to be that one has to REALLY slide the thumb out of the holes way to make the D sound well.
Any tips? Thank you in advance!