What is the minimum age for private music lessons?

There are exceptions, but children aren’t usually ready for private lessons until age 5. Attention span and coordination need to be at a level that is seldom found in students under 5. Your child might be ready for lessons sooner if he or she is reading at a very early age (3 or 4) or is showing enough interest to sit with his or her instrument for over 30 minutes at a time.
To give your kid a head start, there are music classes that are developed for very young students.