Tuning
An augmented second is enharmonically equivalent to a minor third ( Play) in equal temperament, but is not the same interval in other meantone tunings. In any tuning close to quarter-comma meantone it will be close to the 7:6 ratio of the septimal minor third. Hence the distinction is not, as often thought and even taught, a purely formal and contextual one, but reflects the tuning practice of much of the common practice period.
The 75:64 just augmented second arises in the C harmonic minor scale between A♭ and B. Play
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