"It must be left to students of musical semasiology to account for the psychological association that exists between the spiritual concept of goodness and saintliness and the notational accident of the absence of sharps and flats in the key signature, which results in the 'whiteness' of the music."
There are two factors that can make music notation look whiter: one is the absence of sharps and flats, the other is the use of longer note-values (whole notes and half notes).
The first was the subject of an edict from the Council of Trent in the 16th century: the church authorities wanted to clean up the (to them, unnecessarily) complications of church music, including sharps and flats. The product of this reform was . . . Palestrina.
A composition teacher I attended once told me that in his choir-boy days he would judge the interest of a piece of music by how white it looked. Black meant later, therefore interesting, while white (all semibreves and minims) meant earlier (Palestrina etc.) and boring.
