Have you heard of Bird Vocalization? Sounds like music playing in your ears.
I've never heard of that, what exactly is it?
Basically birds use vocalization with courtship and mating, they also use their melodies for alarms and to keep in contact with each other.
OH, I understand now.  I certainly love hearing them twittering away in the morning.  Do different breeds have different vocalizations?
Bird vocalization
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizations) are distinguished by function from calls (relatively simple vocalizations).
Definition.
The distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with courtship and mating, while calls tend to serve such functions as alarms or
species. Nowadays, the main threats faced by black-bellied seedcrackers emanate from nest predation by rats, snakes and feral cats, habitat over harvest and window collisions (increasing with urbanization).
Behavior.
Behavior Vocalization.
Black-bellied seedcrackers, like most finches, are very social birds and thus maintain strong vocal bonds. They use calls made of low "peenk" to keep contact with each other while foraging or not in sighting positions, whereas their alarm call comprises "terr" sounds. Those are the