Columbia subject headings:
Harvard subject headings:
Mensural notation--Early works to 1800.
Music theory--Early works to 1800.
Musical intervals and scales--Early works to 1800.
Tuning--Early works to 1800.
Princeton subject headings:
Gregorian chants--Instruction and study--Early works to 1800.
Mensural notation--Early works to 1800.
Music theory--Early works to 1800.