Fourfold Theme Fugue
bar1-25 : Theme 1
bar25-34 : Theme 2
bar35-47 : Theme 1 + 2
bar48-63 : Theme 1 + 3
bar64-79 : Theme 1(augment) + Theme 4
bar79-84: Theme 3 + 4
bar85-88 : Theme 1(diminution)
bar88-107 : Theme 1(normal + augment + diminution) + Theme 2 & 3