“What’s the point of modes?”
Teachers have a hard time answering this extremely common question, either because they don’t know or they can’t relate. It’s a bit like asking an interior designer “What’s the point of shades of colors? Do we really need them or can we just stick to the major half dozen or so?” No, we don’t really need them. Colors and shades of color are relatively unnecessary. But it’s kind of the whole point of the profession, not to mention a huge enrichment to most people’s lives.
The point of music is the same as painting or standup or story telling or any other art: to communicate emotion landscapes. Modes are note sets that each have their own emotional content, but they are subtler than most common scales and alterations. Major scales feel happy; minor scales feel sad; blues scales feel grimy. But how does the dorian mode feel? That’s complicated.
If the most common story settings are “Once upon a time,” or “The other day I…” those would be our major and minor scales. But the Locrian mode might be “Call me Ishmael” and lydian might be “It was the best of times; it was the worst of times.” These stories might be more nuanced and not appeal to as wide and audience.
However—it is not the student’s fault that modes are often taught in a terrible, terrible way! Teachers often talk about the mode numbers and relatives. That’s ridiculous! “A minor” has nothing to do with the key of “C major” except for the fact that they have mostly the same number of sharps and flats. Why would you even bring that up, much less bringing it up first, as an intro to the topic!?!
“What was Abraham Lincoln like as a person?” “Well you’ve seen a slug, right? The two of them share about 70% of the same DNA, so just think of a slug, but he was president.”
In the end, modes are just a tiny subset of the possible note families we can use to create different feelings. They are related to other scales that have the same sharps and flats (“relative” scales), but more importantly, they are related to other scales that evoke similar emotions. Aeolian and Dorian share a lot of similar emotions, but are subtly different.
But one of the biggest uses of modes is in short, contextualized bursts. For example, if a D minor chord is being used as a 2 chord, we might play in D Dorian during that chord, but if it’s acting like a 6 chord, we might use Aeolian.
I know this is a bit of a game changer to say that a whole song won’t be in one mode, but the same is true for keys: even cheesy pop songs sometimes change keys mid-song. That doesn’t mean that there’s no point in learning keys—quite the opposite. It helps to be so familiar with multiple keys that you can switch between them smoothly. Likewise, once you are familiar with your modes and scales, they will be tools to switch between multiple times within a single song.
If you ask an interior designer “What’s the point of shades of colors?” the real answer is “There is no point in shades until you can tell the main ones apart. When shades are relevant to you, you’ll start to see them. But if you spend a lot of time looking at different shades, they will become relevant sooner.” The same is true for modes and special scales.