Why do people interpret music comprised of minor chords/harmonies as sounding sad or gloomy?
Dissonance/consonance is really a spectrum… To put musical intervals in visual terms, imagine three printings of a picture in a newspaper, with red, yellow and blue layers. One print is clear, the colors are lined up, edges are clear, the picture is not blurry. This could be likened to consonance. The second picture has been poorly printed (or purposefully misaligned by an avant-garde print-maker) and the different colors are printed slightly off of each other (we’ve all seen this in a newspaper). Edges are confusing, blurry, and the picture may make your eyes hurt, even make you sick to your stomache to look too long. This could be likened to extreme musical dissonance. Remember that the color prints are close, but not exactly matching. They interfere with each other. Now imagine a third print. The colors are again offset, however, this time by a wider margin, perhaps 1″ away from each other in a 5″ picture. While disconcerting, the images don’t interfere with each other in the sens
SalientAlien’s answer is good. Mine only expands a little and is less “sciencey”. The defining notes in major/minor keys are the 3rd and 6th. Science wise, the numbers of vibrations in the air (in space, nobody can interpret your music as sad) caused by a major 3rd and major 6th are relatively “consonant”. This means the ratios are more comfortably matched. Consonance is not unsettling to hear. Complicated (uncomfortable) vibration ratios in music are referred to as “dissonance”. Dissonance has several meanings in English, all of which relate to conflict or incongruity. It’s not a massive leap, then, to think that people would start using dissonance to convey sadness, unsettledness, etc, and consonance to deliver happy messages. Once someone got that ball rolling, it became part of our musical language. It’s a meme. If I wander over to the piano and plonk down one hard, long, G minor, you might think I was about to sing a sad song, not really because it’s sad in itself (it’s only disso
