Normal sudoku rules apply. The red/yellow lines are a famous tune put into C major using notes of the scale from 1 to 5 (1=c, 2 =d etc). The yellow line is the first line of the tune and the red line is the second line of the tune. On a green line, adjacent digits have a difference of at least 5. A purple line contains a set of non-repeating consecutive digits, in any order.