A Great Fingering!
Every now and then you might be stumped for a fingering, which was the case in a recent piece that we premiered in Pacific Symphony. We were asked to trill C#-D, in the fourth octave (the five ledger line C#). I could not find a fingering anywhere, so I set about to figure it out. So, here it is! Your flute must have a C# trill key to make this trill work, and I'm thankful that this option is becoming a real favorite and almost a standard key these days. I've never seen this fingering written down anywhere...so......
You will be moving the C# trill key as the trilled key: Finger C# as LH: 2 and 4, RH 1 but use your second finger here: you need to move your index finger over to trill that C# key. Voila! A decent half step trill!