My Observation of Human Perception of Frequency in Relation to Music

In Professor Dobrian's article, he states that humans can perceive frequencies between about 20-20,000 Hz. That being the case, then it is interesting to note how minimal music is in that world. Assuming that about an 90-note range is involved musically, then it can be observed that in music only a mere fraction of frequency perception is utilized. With A4=440Hz, then that means that the overall range that we hear in music is only about 30-4,000Hz. With humans being able to perceive about 20,000 different pitches, it is fascinating to observe that music (excluding overtones) - the most sophisticated manipulation of sound - only directly presents humans with about 1/5 of their perceptive potential.