Can necessarily mean “the alternation of two musical tones a diatonic 2nd aside” or “a sound resembling a musical trill.” The flute-like trill with the wood thrush is perhaps the most wonderful song of any North American chicken. The descending trill of its relative the veery isn’t too shabby, either. https://socialclubfm.com/story8746716/the-basic-principles-of-birdwithmostwords-com