Music is an integral part of the life of almost every individual. Whether you listen to popular, alternative, or classical, you listen. So what is it about music that transcends our differences and compels us to keep coming back to hear more?
Most people, when questioned, would probably answer that their favorite part about music is its ability to invoke emotion—music can make you “feel things”. But not only does music release endorphins and other chemicals, it stimulates multiple areas of the brain .
It may seem strange that simple vibrations can produce such a complex response by our brains—but these vibrations are how we experience the world. Still, why are the vibrations produced by music so much more powerful than other sounds?
One particularly intriguing mystery is that of major versus minor. A major triad, constructed of a tonic note, its major third, and its perfect fifth (a minor third above the third), provokes happiness, while a minor triad, constructed of a tonic note, its minor third, and the perfect fifth (now a major third above the third) makes listeners feel sad. Why does changing the frequency of the vibrations change the way we feel about them?
One article from Quora cited a study done by Tufts University that analyzed the speech patterns of stresses reading different emotional scripts. Interestingly, it found that when the actresses read the “sad” script, the minor third appeared in the pitch contour of their speech. In other words, their voices tended to oscillate between two pitches approximately a minor third apart. In contrast, the major third interval tended to be produced when the actresses read “pleasant” or “happy” scripts, as did the major sixth (the inverse, in a sense, of a minor third).
A commenter on the same article cites Harmony Explained, a scientific theory of music. According to Alex Schmidt, the phenomenon called the harmonic series is responsible for the emotions related to certain intervals. In essence, the mathematics of harmonic theory show that when a certain pitch on an instrument is played, it is not the only pitch produced—it is simply the lowest partial, or sine wave frequency, and therefore the one perceived. These partials are members of complex tones—sounds produced by the instruments we are accustomed to hearing. The timbre, or tone, of these instruments is pleasing because they produce these complex tones with multiple frequencies embedded within them. When a pitch is played, some harmonic frequencies can be perceived above the initial pitch: these are known as overtones. For the most part, all overtones produced by a complex tone are mathematically an integer multiple of the lowest base frequency (the original pitch). According to Schmidt, the major chord is the most stable chord because its harmonic elements are the easiest overtones to hear. This therefore makes it the most “pleasing”, producing a pleasurable effect. The minor chord, though also stable, is slightly less stable than the major chord. Schmidt theorizes that this is because the brain recognizes the pleasing intervals (a major third and a minor third together) but in the wrong order (see third paragraph above). Because it is so close to the most stable chord, the brain perceives it as almost happy, but not quite. Other chords, such as diminished, augmented, and chords with added scale degrees (like a seventh chord) are not as easily perceived as parts of the harmonic series, and theoretically this is why they sound incomplete and strange to the ear.
One last music blog discussed the probability that emotional responses evoked by music are nothing more than social conditioning. Western music, once one of many musical systems, has now become the primary way that the majority of the world experiences recreational sound. In this system, there are some “perfect” intervals that can be used in either major or minor, and some that change depending on the quality of the chord. These perfect intervals are the first scale degree, or tonic, the fifth (or dominant), and the fourth (or sub-dominant). Seconds, thirds, sixths, and sevenths change depending on whether the musical key is major or minor, although the second generally stays major in any key. The perfect intervals, which can be used in either major or minor keys, have no specific emotional association because they appear in songs of both associations. The others, however, generally appear in one or the other, and therefore have a stronger association—and especially the third, as it is the determining factor of the quality (major or minor) of the Western chord.
It has long been traditional to use major chords for happy tunes and minor chords for sad ballads. However this trend originated, it has been so ingrained in our ears since before the days of musical pioneers like Bach that there is little chance of effecting a dramatic shift in the way we feel about music—so keep listening.