[greffer]

A difference may be that you start speaking around age 1/2 and then the written word follows about 5 years later. If you start learning to play the piano at age 8 and wait for 5 years to be introduced to any musical notation, then this will be very late and will have cost you 5 years of training and getting used to reading (and writing) said notation.

[analog31]

Indeed, and this has been an area where music education has gone back and forth. Historically, the popular Suzuki teaching method started with playing by ear (and being told where to put your fingers) exclusively. Today, "Suzuki" teachers generally add reading to the curriculum, not right away, but fairly early.

An amusing bit of reverse psychology, the kids who learn to read can begin to have more fun on their own than just playing the boring stuff from their lessons. This motivated both of my kids.

These days, the person who is utterly helpless without a sheet in front of them is a rare exception, except maybe on piano. But there are two things "wrong" with the piano: Not just the notation, but the focus on playing it as a solo instrument. In my view, in addition to reading and ear training, the other component that needs to be started as young as possible is playing with other people. The Suzuki method does emphasize this quite heavily. It's hard to do with pianos.

[greffer]

I fully agree. Compare to natural language: Monologues have their place, but speaking to others is essential to learn, and so is interacting musically with others.

I do also think that some education philosophies focus too much on notation, but being illiterate (as in: not being able to read musical notation) is restricting quite a lot what you can do and how you can learn.