The Sudoku fever has finally reached the world of music. 'Musik-Sudoku' is the first musical variant of the popular number-placement puzzle. Instead of numbers, the seven solfège syllables Do Re Mi Fa Sol La Si have to be entered in a certain order. The really special thing about it is that the notes in the marked boxes match the beginning of a famous melody – from 'Let it be' by the Beatles to Mozart's 'Kleine Nachtmusik' –, thus providing a musical clue to the solution. The puzzles of varying ...