Does your tongue love the taste and texture of hot fudge? Do your eyes enjoy the sight of it slowly invading and usurping the territory of vanilla ice cream? Is there some subtle olfactory amalgam of maraschino cherry/chocolate/vanilla bean that sends your nose atwitter?
As a vegan, I don't endorse any of the above except maybe the cherry sans the Red #40 (I prefer the sensory delights of a tofu/wheatgrass/sprout surprise naturally). As a musician, I can tell you that there is a musical equivalent to a hot fudge sundae: intervals your ear loves to hear. Conversely, there are leafy green tonics in the musical world and if you hear one of them you will want to move quickly to dessert to cover up the earthy taste...unless you're an outlier like me.
When Pythagoras broke his flute in half in a fit of anger over GoogleMaps' inability to give directions solely as a series of hypotenuses, he noticed something pleasing when he played it that almost assuaged his ire. Let's say the first flute played the note "A" that vibrates at 440 Hz. The half-flute also plays an A but will have twice the frequency: 880 Hz. When played together they form an interval called an octave, which is very pleasing to the ear (provided both flutes are properly tuned, else it will be auditorture) as are its mathematical variants. I won't go into all of those because I want to introduce the so-called dissonant intervals, i.e. the pairs of notes that create tension that you want to hear resolve (into consonance, of course. Dissonance is for dissidents!)
First, let's take a gander at two almost-octave intervals: the major seventh (a half-step short of an octave) and the minor ninth (with a half-step too much). Remember that these have been historically unpopular intervals that were surely thought to incite riot. So it may come as no surprise that one of the best examples of a minor ninth is the opening to Rage Against the Machine's "Killing in the Name Of." In stark contrast, John Tavener's "The Protecting Veil" frequently features musical sentences ending with the cello descending into a minor ninth. This was my first introduction to the interval and the unsettling feeling it gave me stayed with me and I continue to use it in my own works, following my aesthetic that art should always unsettle (a topic I will expand in another post).
Quickly, we consider the minor second, which is a half step itself (two adjacent piano keys). Everyone knows this as the infamous prelude to a shark attack in Jaws. Finally, there is the augmented fourth aka diminished fifth lovingly known by such monikers as the tritone and the Devil's Interval. Despite the early church's proscription, bad boy madrigalist Gesualdo used it here and there. Not nearly so scandalous in our modern times, it forms the musical backbone of "Cool" and "Maria" from West Side Story by Leonard Bernstein.
I've played them for you below, trying to illustrate where they are located on the piano should you like to learn them too and join the dark side.
