We would all like absolutes about our child’s development, with obvious markers and a check-off list so we know that our child is on schedule.  Music development doesn’t work that way.  Nor does language development.  Each child goes through stages in both language and music that have been documented extensively, yet each child goes through the various stages in his own way, and at her own pace. 

Talking to an infant and encouraging babble is essential to language development.  Singing to an infant and encouraging “Music Babble” is essential to music development.  Your non-verbal child manages to communicate emphatically and even understand, yet ignore your requests.  Similarly, the non-vocal little musician communicates a great deal about his musical understanding.  Here is a Reference List of Musical Behaviors you might observe with Rhythm and Tonal Activities.  Check it occasionally as your child develops.