Can mean “the alternation of two musical tones a diatonic next apart” or “a audio resembling a musical trill.” The flute-like trill with the Wooden thrush is Probably the most beautiful music of any North American fowl. The descending trill of its relative the veery isn’t much too shabby, possibly. https://thesocialcircles.com/story3903547/the-fact-about-birdwithmostwords-com-that-no-one-is-suggesting