Birdsong is patterned vocal behaviour used by birds in contexts such as territorial defence and mate attraction. Song production, auditory recognition and acquisition of a local song pattern are different processes. In many songbirds, hearing other individuals during development contributes to the song later produced.
In controlled chaffinch studies, hand-reared birds exposed to different auditory examples developed different song patterns. Artificial tutor sequences assembled from suitable notes could also be incorporated. This made auditory experience experimentally separable from the species-typical constraints on what could be learned. [ref]
The learning of song patterns by birds, with especial reference to the song of the chaffinch Fringilla coelebs by W. H. Thorpe. 1958, summary: hand-reared birds and artificial Song Tutor sequences
The comparison does not imply that every bird learns its vocalizations in the same way. New to topics? Read the docs here!