When given piano lessons in conjunction with a math software program, the whole second grade of a California test case school performed at a fourth-grade level of math comprehension. In fact, the top half of that second grade class performed at a fifth-grade level of comprehension.

From: "Music Spatial-Temporal Math Program for 2nd Graders Enhances Advanced Math Concepts and Stanford 9 Math Scores"

Available here: MIND Institute web site