I went back and gave them a listen again. Got my score up to 38 (1,2,4,6,7,8,9,10,12,13,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,31,32,33,34,35,38,39,41,42,43,45,46, and 49). I'm almost certain I own a copy of 40, and 3, 5, 37, and 48 are really bugging me.