What about time ? the relative ratio of durations and displacement between sounds is , to me , as important as tonal frequency (well even if at the end of the day , both are frequencies on different abstraction scales).
the article focuses on tonality so I didn't even think to mention rhythm but you're right, rhythm does have a frequency equivalent which is not always on a different abstraction scale. 32nd notes in music played at 120bpm have an audible frequency of 64hz.
