c = 5 x d + 2

Here's a fascinating (German) article about Swiss physicist Guerino Mazzola's mathematical theory of music, an important part of which is Fux' rule which I've quoted in the title. In essence, it shows the relationship between consonant and dissonant intervalls in western music. Based on that, Mazzola develops a comprehensive and explanatory model of music in his book The Topos of Music.

What thrills me most about the idea is that the differences between western music and indian music for instance are just a matter of parameterisation of the modell. Consequently, it should be possible to have Beethoven's Ninth Symphony "translated" into raga - and the other way round! Imagine whole new universes of musical masterpieces becoming available to the uninitiated ear! If this is really true, I hope it will happen very soon. Possibly, Mazzola's role in music might be similarly revelatory like that of Luther in religion, who brought the text of the bible to the common man because it was only available in Latin before he translated it.