What type of behavior is a bird song, learned or innate?

The tendency of the bird or the inclination to sing is innate in birds, however, the song, which is sung is learned. There exists an innate tendency to sing a song whether the bird is in seclusion or not. The birds possess sensitive/critical periods when they can produce memories of the songs they learn. The anterior forebrain pathway or the anterior vocal pathway is the template for learning a song by the bird.