This set of six-square puzzles includes the difficulty levels of easy, medium-easy and medium.  Each of the 24 puzzles is labeled accordingly and they get progressively more difficult as you move to the end.  Like the familiar number version, the rules for solving these puzzles are simple: put one, and only one, whole, half, quarter and eighth note, and whole and half rest in each row, column and 3 x 2 box within the larger grid.  All ages.