You don’t mention the age of your child, Kevin, which makes it somewhat difficult to answer. However, it is a very thoughtful and well-articulated question and certainly deserves an answer.
I would say that your first job is exposure. Let him hear music. Teach him songs and sing along with him. Take him to children’s concerts, perhaps staying for only part of one if he is a preschooler. If possible, take him to the stage during intermission so he can get a close look at the different instruments. If the family has a piano or a keyboard, let him strike the keys and hear the different sounds. Pianos are such a big financial investment that parents sometimes forbid their young children to touch them. However, there is actually very little damage a young child can do to one. Help him find Middle C and make simple tunes for him by going up or down a few keys.
The piano isn’t the only instrument that appeals to young children or that they can use. The Suzuki Method of teaching violin is highly respected and used worldwide, and there are research data available demonstrating that children who learn to play the violin by the Suzuki method have better than average math skills.
If anyone in the family plays an instrument, help him learn to sit and listen as it is played. The best way to do this is to hold him on your lap or sit close to him during the “performance.” Once you get any indication that he is interested, find a good teacher for him. He’ll have a lifetime of enjoyment from your thoughtfulness.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.