The trouble with being able to read music is that you can neglect your other senses. When my son was 10, I arranged for him to have guitar lessons with a teacher who was patient with his difficulty in learning to read music. (He's severely dyslexic.) He had no difficulty in composing his own music for someone else to write down. His peers struggled. I used to rely on my ears to sing with others, but now feel I need the music, unless I have worked hard and learnt it off by heart.