Some years ago I found this canon enigmatico from Manuel Cardoso, a portuguese composer from the 17th Century. The canon enigmatico was a common praxis in the 16th Century and consists in hiding one of the polyphonic voices of a piece. Instead of music notation the composer writes in the Tenor II or Alto a text that should be deciphered to reconstruct the music. Manuel Cardoso wrote 1625 one canon enigmatico which as far as I know was only deciphered by the musicologist Mário de Sampayo Ribeiro in the 20th Century. The sentence is this: Qui sequitur via recta non ambulat in tenebris which could be translated as who follows me through a straight way will not be walking in the darkness. The part who follows me through a straight way means that you should read the Superius I backwards from the end to the beginning. The second part will not be walking in the darkness means that you should take the Superius I and read only the white notes (whole and half notes) and ignore the black ones (quarter and eight notes).
A fascinating form of obscure mystery that once solved allows the piece to be performed with all voices.
This White Keys Music means to be an Homage to Frei Manuel Cardoso. It is an algorithmic process where only the white keys are used in the sense of pitch. All the notes and rhythms are, in this case, from Chopin except for the black keys which are substituted by rests.
The first examples are from Chopin op. 18 Grand Valse Brillante and Etude op. 10 nr. 5 (Black Keys)