Music is the best way I have ever found to express and understand ideas, feelings and emotions throughout my life. Moreover, the most recent researches state that music also structures human mind.

In the link below you can find some stated quotes about music:

http://www.quotegarden.com/music.html

A mathematical concept, the parameter, is also used in music meaning separate variables. In our case, parameters are: rhythm, length, pitch, melody, intensity, timbre, dynamics, character, articulation and attack. New parameters that make musical language more complex have been given by contemporary music.
Life evolutes permanently too and bowls us new challenges that lead us to more and more complex new ways of life and communication.

The first step that I suggest you in this search experience consists on approaching parameters that will help you to understand better birds’ song musical learning.

Let's start with:

High sound, low sound, rhythmic song and melodious song.
Sound propagates in space through a medium that might be gas, liquid or solid. Sound waves can be interpreted when an oscillation produces a vibration in our organs of hearing. Meanwhile, rhythm is the proportion and order of a sound impulse extended in time and may be regular or irregular.

High sound: propagated by a high number of vibrations.

Low sound: propagated by a low number of vibrations.

Rhythmic song: uses a recurrence.

Melodious song: group of sounds that follows a fix pattern and uses different intervals (distance in pitches between two notes).