We get asked this alot and it’s an interesting one. Before we answer the question directly we need to speak to the underlying idea here – which is that someone can be “musical” or “not musical”. What parents usually mean here is, does my child have a talent for music, which again carries the idea that someone must have a talent or skill in music to do music.
Talent and natural skill is powerful but only part of the picture. A talented musician may for example under-practice or prepare for performances because it comes easier, only to find themselves behind the ball when they arrive. An intuitive musician may also be someone who creates well and can play naturally but remains mediocre technically as they do not do the hard work of technique.
We would suggest that the better question to ask is “Does my child like music?”. Once there is a spark of interest the method and approach can be tailored to however the student would like to, taking on board whatever natural talent (or lack of talent) they come with.