Cool Facts via All About Birds
Each male Lazuli Bunting two years of age and older sings only one song, composed of a series of different syllables, and unique to that individual. Yearling males generally arrive on the breeding grounds without a song of their own. Shortly after arriving, a young male develops its own song, which can be a novel rearrangement of syllables, combinations of song fragments of several males, or a copy of the song of one particular older male.
Song copying by young male Lazuli Buntings can produce song neighborhoods, in which songs of neighboring males are similar.