Karaoke machines like toys all have safety rating for age appropriateness. So, not all karaoke machines are safe for a 4-year-old. Included within each of the items listed on our list is an age rating that is given to using by the manufacturer. It is important to make sure that the karaoke machine that you decide on it age appropriateness. To make sure that a karaoke machine is safe for a 4-year old please refer to each item.