It’s sort of ridiculous that I’ve never studied even the very basics of Indian music, like what are the ragas. Thanks to my friend Todd Trimble I’m dipping my toe into it. And it turns out that in Carnatic music, one of the two main kinds of Indian classical music, the 72 Melakarta ragas are just subsets of the usual 12-tone scale!
I just learned why there are 72. Let’s use western notation and call the 12-tone scale
To be a Melakarta raga, a subset of these tones needs to obey some rules:
• It needs to contain C and G. (So, it needs to have the tonic and perfect fifth — a very reasonable constraint by western standards.)
• It needs to have 2 of the 4 notes D♭ D E♭ E — so that’s 6 options. (In western terminology we’d say it needs to have a second and a third, but the second can be minor, major or augmented and the third can be diminished, minor or major.)
• It needs to have either F or F♯ — so that’s 2 options. (So, it needs to have a fourth, which can be perfect or augmented.)
• It needs to have 2 of the 4 notes A♭ A B♭ B — so that’s 6 options. (So, it needs to have a sixth and seventh, but the sixth can be minor, major or augmented, and the seventh can be diminished, minor or major.)
This gives a total of 2 × 6 × 6 = 72 options!
All this seems very reasonable by western standards: it’s just very systematic and thus includes more cases than the most common western modes. Probably really good jazz musicians think about all these scales.
For example, Mayamalavagowla is one of the spicier ragas recommended for beginners on VoxGuru:
It’s spicy because it has a minor second:
In western terminology it’s called the ‘double harmonic’ or ‘Byzantine’ scale, and it was famously used in Dick Dale’s surf rock classic Misirlou:
But beware! There are many more ragas, called ‘janya ragas’, derived from the basic 72 by leaving out notes and other tricks. This calculation claims there are 28,864 possible janya ragas:
• Rudi Seitz, Janya ragas: 24776 or 26864?
However, he counts two janya ragas as the same if they have the same notes, even if they have different Melakarta ragas as ‘parents’. This may not accord with actual practice. And I don’t know what fraction of these ragas are commonly played.
There is more information here, but it’s not open-access so you may need a friend to get it:
• Jom Kuriakose, Veena Suresh, Shrey Dutta, Hema A. Murthy and M. V. N. Murthy, On the concept of Raga parentage in Carnatic music, Journal of New Music Research 51 (2022).