Find the Greatest common factor, the GCF, of 4, 8, 6, and 12. It is 2, because 2 is the greatest number that goes into each of those numbers evenly. So 2 people per row. Then divide the number of each instrument by 2 to get the number of rows needed for each. 4/2 = 2 rows of piano players, 8/2 = 4 rows of tenor players, 6/2 = 3 rows, and 12/2 = 6 rows of saxophone players.
