This piece is just about as far from tonality as I get. My atonal essays never seem more than clumsy and gratuitous (I have little to say therein). But actually, this piece probably fits the "shades of gray" theme quite well. Randall Giles, now living and teaching in the south of India, is an atonal composer whom I met during a period that I was living in Oregon, Giles's home state. He is a choral composer whose atonal sonorities surprisingly make one think of Palestrinafor a large cathedral space amplifies their considerable beauty.
The intriguing tune he provided is based on the octatonic scale, an elegant sequence of whole and half steps that provide an eight-note scale, repeating exactly at each octave, yet evading any sense of a tonal centerwhile the music based on it seems to yearn for one.
Thus, it seems to me to exist in that gray area twixt tonality and atonality.