I am not really saying that. Relative pitch and perfect pitch are mutually exclusive, while both taking quite much to learn, depending on individual. There’s also a multitude of people who have a perfect pitch and who are second rate musicians at best, so it is not a magical path to musical talent people often think it is. You could actually hamper your child’s musical progress with trying to teach them perfect pitch specifically. As with any arts, best thing you can do to your child (or to yourself, if you want to learn) is to find them a good teacher. It really is not a job for an app. Music is a socio-cultural phenomenon that we learn through play and social interaction, not just pitch and rhythm. It is not a programming language you just need to learn the syntax and basic algorithms for to become proficient.
If you want your kids to learn music, you should sing to them, dance with them, play music to them and just have instruments around at home they can play with. It same with language, reading, mathematics, anything really. So the imperative form in the title really irked me.
Saying that, I acknowledge this is Show HN and I am not speaking about the project per se (as in how it has been technically implemented), more about the general attitude the title and arguably the projects presents, where we think we can replace things we find challenging in life, arts or culture by shoving some code and a language model into it, but I too much answered as it were and argument someone making in more general post. I try to keep that in mind in the future.