Can mean “the alternation of two musical tones a diatonic next apart” or “a seem resembling a musical trill.” The flute-like trill of the wood thrush is Probably the most attractive track of any North American chook. The descending trill of its relative the veery isn’t way too shabby, both. https://socialwebconsult.com/story3654514/a-simple-key-for-birdwithmostwords-com-unveiled