Another example of how profoundly classical composers think in related tonalities: Preparing a Player's Guide to Mozart's monumental Piano Quartet in G minor, K. 478 (due out next year) I have studied all his works in that key, and in G major, the key of the Mozart Piano Sonata, K. 283 that so troubled me when a child, and which gave rise to my visualization technique, Tonal Refraction. Yesterday I discovered that just before writing K. 478 he wrote three songs, K. 472-4, in the keys respectively of G minor, B-flat major and G major, the same sequence of keys as the three movements of K. 478. Then there is my favorite Mozart song, Das Veilchen, K. 476 which, despite its brevity, is in three keys: G major, minor and E-flat for a slight change.

The discovery elates me.