The Curt Jester brings our attention to Steve's great post on the seven capital sins, Seven Means to Seven Sorrows:
It’s amazing really. From Bach to Eminem, every bit of music is a variation on eight simple notes. The same goes for literature – the Greeks identified roughly a half-dozen different plots, and that’s all anyone has ever used. Unhappiness is the same way. There are only a handful of ways to become unhappy....
Take that, Tolstoy! I hope Steve follows up with a discusssion of the seven cardinal virtues.
Only in the age of equal-12 does that reduction of music make the slightest sense. When Bach modulated on a well or just tempered system he was using different intervals and many more than just seven notes (the octave doesn't really count now). Even in the Equal-12 days, from mid-Romanticism to the full dodecophonic glory of Webern, we use much more than seven notes.