© 2004 Tonalsoft Inc.
© 1998 by Joseph L. Monzo
Donald Lentz, in Tones and Intervals of Hindu Classical Music, gives a description of ancient Indian tuning as a series of "perfect 4ths" and "perfect 5ths", which would give a "Pythagorean" or 3-Limit system of 22 notes ("srutis") to the "octave". He then gives a tabulation of the ratios, but, interestingly, it includes 5-Limit ratios as replacements for some which should be 3-Limit.
I would argue, however, that the theoretical implications of the ancient Indian tuning would allow even more 5-limit ratios than Lentz's description.
Before I discuss Indian tuning, a note about my somewhat idiosyncratic nomenclature:
In my prime-factor notation, 1/1 is referred to as n0 (that is, every prime to the 0th power, which equals 1). I use a measurement of "Semitones" to two decimal places rather than cents, simply because anything less than a cent is usually insignificant, at least for purposes of music-theory, and it relates better to our familiar old 12-EQ scale. (It's really the same as cents, just with a decimal point.)
Now, on with the show:
Lentz gives the most ancient Indian fretting as a series of "perfect 4ths and 5ths". This makes a lot of sense, as it could have been easily accomplished by ear. It can be measured for one "octave" on a single string in two separate procedures, as follows (frets are numbered in order of placement during the procedure, not in order of pitch):
PROCEDURE OF TUNING ANCIENT INDIAN SYSTEM: