What's the right age to introduce music instrument to your kids?

Basically, I asked myself what is the right age to introduce music instruments to  your kids? Based on my research and reading it all depends of what is your goal for your kids. If you want your kids to be on the stage and have mastered one instrument you should start at the early age.

My daughter has been asking to play a string instrument though I am not convince yet that she will take time to  practice every day.I did not answer her yet but am searching and found this string instrument store and has an interesting products.