Not unusual, historical. The primality of the diatonic scale in Western music goes way back, and even now we use the language of the diatonic scale when trying

Not unusual, historical. The primality of the diatonic scale in Western music goes way back, and even now we use the language of the diatonic scale when trying to describe each of the twelve notes in our system. But it's more than just names: it's ingrained in the structure of our music as well, as to what notes and harmony are chosen. In the early 20th c. a more expansive, what we call "atonal," form of music arose that used the chromatic scale without any particular referent to a diatonic system. Some music analysts and teachers even started to replace note names with note indices to avoid diatonic confusion. Atonal composition became popular among avant-garde and film composers in the mid-20th century, and is still with us. The diatonic system, though, has proved quite tough to kill off.