This is definitely the clearest explanation of just intonation I’ve ever seen. In just intonation (as opposed to equal temperament), all the notes are in whole number ratios with each other. Standard equal temperament, on the other hand, takes the octave as a 2:1 ratio and then splits it up into 12 even parts. The frequencies of these parts are close to, but not quite, whole number ratios.

See? Describing it makes it practically impossible to understand! Watch the video and hear the exacerbated wiggliness of equal-tempered chords. The video is an ad for some system that automatically fixes up your intervals, but if you like oscilloscopes, you won’t want to miss this! (How’s that for a sales pitch?)

(via immanent discursivity)