Years ago I heard this bird every morning during the late spring and early summer, and I’m pretty sure it was in Germany. It would sound very early while it was still practically dark and was about the first bird I would hear. Never since have I heard anything like the dulcet tones that emanated from this avian’s thorax. Since this was in Europe, I thought it might have been a nightingale, seeing as those are famous for the beauty of their singing. But having found sound clips of nightingales, they don’t come close to what I heard. They trill and tweet pleasantly, but it was as if the bird I heard was was playing a musical instrument. In fact, here is my approximation in musical notation:
I have no idea what the actual pitches were, but to keep thinks easy I’ve written it in C. Naturally they are only an approximation; I’m sure the bird didn’t sing an exact inverted fifth interval at the beginning as I have written. Also on the high E would have a little upward “bend” if you will, through the tie.
I hope Colibri reads music. If not, the melody is the same as that four-note trombone passage they played on ST:TOS whenever there was an establishing shot of some majestic alien city or palace, only higher.
Several of the more musical birds (mockingbird, nightingale, etc.) will incorporate anything they hear that sounds even remotely birdish into their songs. So what you heard might well have been a nightingale performing something composed for flute, if it heard a flute playing it at some point.
Or it could have been a starling imitating something they’d heard. They are merciless imitators. We used to hear a starling singing the first part of the curlew song. We were about 10 miles from the nearest place where curlews would live - there was something indescribably funny and cheeky about it.