The theory of musical relativity
Composers manipulate our emotions by changing the notes being played, switching from “happy” (major) chords to “sorrowful” (minor) chords, or vice versa. But you can also switch between major and minor chords by keeping the notes the same and changing the velocity of whoever is listening to them. That shift in tone, the Doppler effect, is the genesis of a curious idea by Boston University physicist Kaca Bradonji. Bradonji calculates that traveling at about 40 miles per hour toward a musician playing a C-major chord would flip it to a C-minor chord, a new kind of experimental music. On a larger scale, audiences traveling at different speeds would interpret the same score as vastly different works, a sort of aural hologram. Or, as Bradonji says, “one could write ‘path dependent’ pieces, the experience of which varies with the composer-prescribed paths traveled by the observer, who is … moving and occasionally briefly accelerates to different reference frames.” He also suggests composers could drastically change the temperature and pressure of the ambient air, which affect the speed and pitch of sound in similar ways.