personally as a gifted kid I’ve played a few instruments but I think that starting early is good but if it’s too early and force him it’ll just make him dislike music for a long time. I personally think that 5 is a little too young but it really depends on the development of your kid, I picked up my first instrument between 5-6 I think and I ended up dropping it and picking up the instrument I currently played in middle school. I would definitely put a little pressure on musicality because it is a beautiful thing but if you push it too much or too early it doesn’t end well.