This study investigates the relationship between the design of written music and the number of mistakes dyslexic and non-dyslexic children make in reading music is investigated in this study. Previous research shows that children with dyslexia experience difficulties with reading music, especially discerning pitch. Common mistakes of dyslexic students are third-transpositions. Based on insights from previous studies, a questionnaire was developed with several design adaptations of written music. The questionnaire was filled out by 72 Dutch children aged between 8 and 13 years. The results show that children with dyslexia did make significantly more mistakes in reading pitch than non-dyslexic children. The number of mistakes was reduced by enlarging the staves and also by writing all the stems of the notes in the same direction. Using differently-coloured lines in the staff did not reduce the amount of mistakes and was in some cases counterproductive.