Why are scales important when writing melodies

I’m trying to wrap my head around the concept of tonality and how scales fit into it. From what I understand, the relationships between notes (intervals) is at the core of how we write melodies and why they make us feel the way we do. It also seems that scales are built on top of those relationships and then chords are built on top of those scales. I still feel like I’m missing something there. Does anyone else have some insight into this? Wouldn’t it be easier to just base everything off of the chromatic scale instead of having a million different scales and chords? Every interval relationship is already in the chromatic scale, why do we need others??

Listen to jazz…or classical and you’ll see why

Knowing the relationship between different notes is a guide for composition to arrange tones and express feeling through sound… i.e. minor scale is darker, major is brighter…etc…

I think…

Literally overthinking it…get a daw/synth or a musical instrument and start playing it then you’ll start to grasp all the aspects of theory

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You don’t have to see theory as rules. It’s rather used to describe music. It’s not needed to make melodies, but by knowing the relationships between notes you know how to create and resolve tension. It’s a valuable tool to write music


So yes, major is brighter and minor is darker, but my question is why do we have those scales in the first place. Regardless of how you organize the notes, the instrument will only play what it’s tuned to play. My question is, why do we have so many scales. Is it just to organize patterns of notes that composers have been fond of? Or is there a deeper reason more fundamental to how the tonal system was created in the first place?

OK ok… so how do scales help you understand the relationships between notes?

I’m not sure, if I’m knowledgeable enough to give a good explanation. Pythagoras, for example, is said to have discovered the relationship between mathematical ratios and musical tunings (according to Wikipedia it’s probably not true). And over time people made more and more observations about how music works, about what sounds consonance and dissonance, about tension. But there is no universal music theory, because cultures perceive music differently. For example I know that the B in C-Major is a leading tone with a lot of tension. I can use this to create a melody that creates tension and in the end finally resolves to C. And you can categorize chord progressions. If I know that I play over a chord progression in C-Major, I know that C# or F# will sound very dissonant. You can do whatever you want, but if you grew up with Western music, it’s deeply ingrained in you and you can figure out how to use or avoid those conventions.

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Scales are just a subset of the chromatic scale with specific tonal relationships, so they have a specific ‘feel’, because the relationships between the notes are set in a particular way. Dorian mode sounds different than Lydian, and B-Lydian has the same feel as D-Lydian, and so on. Scales and the chords that come from them are just organizational techniques to let you pick a thing you want easily. Sort of like cars and trucks and boats and airplanes are all vehicles, but it’s easier to talk about a subset of vehicles to pare down all the things you don’t want.

There’s stuff way outside of the common structures in western music - eastern scales and temperaments, microtonal theory, atonal, twelve-tone, etc. Some of those get deep into pitch set theory and other formations that have their own notations and relationships. So there’s a lot of ways to do what you’re talking about, and a broad and deep amount of theory in describing the underpinnings of sound and music. Most of it gets mathematically complex pretty quickly, as you’re really talking about frequency ratios and set theory.

Really basically, you want to care about this because 1. most of the learning sources for theory will use it and 2. it’s a common language between composers so someone else can know what you’re talking about. That said, there’s nothing wrong with just plunking around on an instrument until you find things you like. You’ll just be using theory intuitively instead of academically.

Is it just to organize patterns of notes that composers have been fond of? Or is there a deeper reason more fundamental to how the tonal system was created in the first place?

Both, sort of. My understanding is that early musical scales were really just collections of notes that that culture liked. By the time you get to the Renaissance, mathematics and musical theory had advanced enough that people were analyzing the why and how of the intervals, and used that basic knowledge to start creating their own, using the existing theory in new and interesting ways, which really exploded in the 20th century.


Wait…I feel like I’ve read this thread multiple times already…WTF?


Because four current threads ask: what makes tonality?


Destructive simplification;

The answer is, “because there was not always ‘a chromatic scale’.”

We (humans) went ‘scales first’ (usually pentatonic, then modal, then diatonic), and built our instruments that way. Then, we put accidentals in those scales, then the well tempered system (this was the one that truly gave us the tuning system we use in modern times). Then and only then, was there ‘a chromatic scale’ to speak of.

To put it another way, the reason the chromatic scale today makes up the “atoms” of every scale we use, is because we changed the way instruments were built and tuned to make that possible. In years gone by, it mattered which key you were in, because each key was tuned differently and had it’s own little quirks tone to tone.
The well tempered system “detunes all notes a tiny amount” so that every key is now slightly out of tune, but, now all keys are identical to one another semitone-to-semitone, tone-to-tone.

The other half of your question might be, there is a system of notation for ‘just the harmonic relationship itself’ (like, leaving keys and note names out of it).

For melody it’s the tonic sol fa (‘do’ is ‘do’ in every key, ‘fa’ is ‘fa’, si is si, etc).

For chords / harmony it’s the roman numeral notation system.
You’ll often see people use this at gigs.
“Hey Pat, this is an easy one; it’s just I, VI, V, I, (one, four, five, one).”
so in C that’s; C major (I), F major (IV), G major (V), C major (I).
In B it’s; B major (I), E major (IV), F# Major (V), B major (I).

Most session musicians will be familiar with the basics of this, but the system itself goes all the way down, and there are ways of expressing major/minor, inversions, diminished chords, augmented, sus, extended;
VII7b (seven flat 7), ii° (two diminished), IVb9,13, (six major, flat 9, 13) V/V (five of five), iv (six minor), etc, etc.

When you write out the roman numerals tablature, you’re writing out purely the harmonic relationship outside of “what key it might be” so you can play it in any key and it’ll be the same song, just a different pitch, i.e., for keys to suit different singers or solo instruments.

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Most of the music I make is full of melodies yet I have zero music knowledge about chords, scales etc, I never get bogged down in theory, I just press keys until something catches my ears.

One of the most important things about composing music with scales is that composers make use of the note’s natural tendency to ascend or descend. This can be called the “scale degree”. Melody is the stepwise progression of a sounding musical line that is independent of harmony. It is usually sung by a single voice or to a single part. Melody differs from harmony in that harmony is the use of simultaneous pitches, either implied or directly written as a part of the musical notation, whereas melody is the linear succession of individual pitches that make up the line.

The reason why they are important is because scales\keys serve as a guide for writing note and chord progressions. It makes it easier to make music by doing the preliminary theory. Every scale has a unique set of degrees and chords from which to choose when making music. Each scale provides it’s own “tools” to build a song from…that can be especially helpful when you are at the beginning of the song writing process.