I overheard that indian music disputes the notion that 7 notes are equally divided. Hence, people should use tanpura (instead of harmonium or piano) to practice with. I googled about it, and I read that it only plays Pa Sa Sa Sa (or something like that). Can anybody shed light on the topic? Does anybody know some online tanpura that can play all 7 notes? (else how is one supposed to practice?)
See here to play a virtual live tampura and to read more about it.
As you'll find in text:
Also you'll find it helpful to read about quarter tone which is a basic component of many countries' traditional music in Middle-east and Central Asia. As you may know even having smaller note divisions in music of some countries is common.
You can watch a man playing quarter tones here.
The tambura creates a harmonic or resonance field based on the three notes, sa (first), pa (fifth) and higher sa (an octave above first sa) and their OVERTONES. A singer orients himself to these notes and places the other notes by listening for harmonic resonance. This can be done very easily or can take a long while to learn depending on the skill of the musician.
The octave is an artificial creation. That is why the piano is tempered (adjusted) to create equidistant notes.
I play piano and sing Indian music, and am finding very slight nuance differences in pitches because of how the harmonics are tempered (adjusted deliberately) in the piano versus the unadjusted harmonics of the tambura created by 3 notes. The differences are small and not too important, except it makes me ear training a bit more complicated. My ear seems to hear the differences even if I can't hear them, if that makes sense.
Western music is based on the tempered scale because it helps with all kinds of things to do with chords and scales. Indian music relies on natural harmonics even if the notes are not equidistant. Indian music doesn't use chords so they don't worry about that problem.
I hope this helps.