The Meantone family of temperaments strives for extremely clean major thirds in 8 keys, 
pushing all imperfection into the four remaining major thirds. Theoretically correct 
meantone temperaments have eleven fifths exactly the same size. Another characteristic 
is the augmented fifth (actually a diminished sixth) at Ab, the "wolf" fifth. In any meantone 
temperament, one-third of the potential harmony was intolerable.