I don't really like resorting to trill keys when I want to do difficult trills like C-D. For one, the pitch and quality isn't exactly the same. Also, it feels like cheating. I'm willing to use them as ...
I have a C flute, which I recently dug out and am relearning. I've noticed that the first trill key for C-D doesn't work as well for high C-D. There is a change in pitch and quality, much more ...