Here’s a neat idea for a concert that’s going to blow a few minds if it ever takes to the stage.
A combination of three or more notes played together is called a chord. We know that certain musical chords sound happy while others sound sad (although nobody knows why). The mood of a piece of music then depends on the combination of chords being played. More than a few weighty tomes have been written about the way one chord can be transformed into another and the effect this has on the mood of the music.
But Kaca Bradonjic, a physicist at Boston University, says that musicians appear to have ignored one of the fundamental ways of changing the pitch of a note: the Doppler shift. He points out that it ought to be possible for an observer moving at a specific velocity to hear a sad sounding note as a happy one and vice versa.
Which means that the mood of a piece of music depends on the relative velocities of the audience and performers.
He calculates for example that to hear a C major chord as a C minor, the listener would need to be travelling at about 43 miles per hour, directly away from the source. That’s a fair speed. And the accelerations necessary to vary this effect from one note to another during a concert would make this one helluva roller coaster ride.
Talking of which, a (very quiet) roller coaster might be the perfect venue for the first concert of this type.
Ref: arxiv.org/abs/0807.2493: Relativity of musical mood