Are all modes/scales in a given key signature perceived as equally bright/dark?

Question

Many people experience certain keys to be "brighter" or "sharper" relative to other keys. Keys with more sharps than flats are reported as being "brighter" and keys with more flats than sharps as being "darker." This question cites a book that mentions this, and additional citations are below. To give one example, many find a song written in AMaj to sound brighter than a song written in E♭Maj.

My question is: has any trend been found that correlates this same quality of brightness/darkness (which is normally associated with particular keys) with the particular mode? For example, among people who have a consensus that AMaj is brighter than E♭Maj, would a song written in AMaj sound brighter than a song written in F♯min? Or do both songs elicit the same experience of "brightness" because they both have the same number of sharps?

I'm not wondering about whether one song would sound happier (as this question asks). Rather, I'm asking about a different phenomenon that has less to do with an emotional response and more to do with an associated perception of brightness in the sense of color/contrast.

Note 1: this might be interpreted as a personal poll, which I'm hoping to avoid in the answers. Just as a consensus exists that many people find, e.g., AMaj to be "brighter" than E♭Maj, I'm wondering if a similar consensus exists about whether or not the particular mode impacts this same perceived brightness.

Note 2: the phrasing "keys with more sharps [than flats] are brighter" might be an imperfect description of the phenomenon I'm referring to. I don't want to imply that anyone hears D♭Maj as being brighter than C♯Maj. For more detail on the phenomenon, see below.

---

Here are a few descriptions of the phenomenon I'm referring to.

The Harvard Dictionary of Music

Keys with sharps in the signature are often said to be bright and keys with flats dark.

https://musiccog.ohio-state.edu/Music838/exam_questions_answers.html:

What is meant by a "key characteristic?" The association of certain musical key signatures with a specific subjective quality or emotion. e.g. E major as "bright & piercing."

http://biteyourownelbow.com/keychar.htm:

Key Characteristics

Today many musicians claim to hear the different characteristics very clearly, and associate them with the emotional quality of the music. They will tell us that music played in the "open" key of C major---with neither flats nor sharps in the key signature---sounds strong and virile; played in the key of G, with one sharp, it sounds brighter and lighter; in D, with two sharps, even more so; and so on. Every additional sharp in the key signature is supposed to add to the brightness and sparkle of the music, while every flat contributes softness, pensiveness, and even melancholy.

Answer 1

In equal temperament, the mode impacts the brightness or darkness of the music far more than the key, from lydian on the bright side (it's the cartoon mode, after all!) to phrygian on the dark side.

In addition to Tama's excellent answer above on timbres and how they affect brightness, it's also worth considering that before equal temperament, each key did in fact have a unique set of mathematical ratios between pitches. The major third C-E was different from the major third Ab-C or G-B. So, Bach's C major is not quite the same C major we have today. Equal temperament should render all keys equally bright or dark, save for the timbre issue.

Answer 2

When you write a piece in a certain key you're really writing with a tonic note in mind. That is, one note is considered the note on which the piece rests and which all other notes are compared to. Different notes are either higher or lower than each other depending on the instrument's range, the composer's intentions, and the limitations of the player.

For instance, on a guitar the lowest note is (usually) E natural below the bass clef. Technically this would make E major the darkest key on a standard tuned guitar while Eb major would be the brightest (since it's the highest note on the lowest octave).

The human voice is also a big determining factor of what keys people consider brighter or darker. Sopranos and tenors have the highest voices of women and men while Altos and basses have the lowest. I consider the keys of C and F major to have a 180 degree relationship; that is, they are as far apart as can be and are considered the lowest comfortable keys for the 4 singing ranges. Also, unlike most people, I consider C major to be a "flat" key because most flat keys have a C natural in the scale while only one sharp key has it (G major). It's also the 5 of F major.

There's also a psychological factor to consider. When you see the note Eb you immediately compare it to E natural and assume that it must be darker if it's lower. In reality, they're only a half step apart and both are played in a similar range. F major is a half step higher, so wouldn't it be considered brighter? I think the biggest factor is that all keys are based on modifying C major, so most people will practice C major constantly and ingrain in their heads the natural notes. Thus when they play G major and raise the F up it feels brighter. Moreso when playing D major since its tonic is a whole step above C along with raising C itself.

It really depends on where you put the tonic in relation to the other notes and what range the tonic is played within. You can put your 4 voices on their lowest notes (like Eb2 on bass and Eb4 on soprano) but if you raise those up and octave it suddenly sounds much brighter. What makes A major feel brighter is that it's easily reachable on top of the treble staff while still sounding good to our ears (eg A5) while a note like Eb6 is quite shrill. It's a comfortable high. A is also a high note for a bass, since A below the bass clef is inccedible difficult to sing. For a bass singer Eb would be a quite bright key, while for a soprano it would be fairly mellow.

In short, timbre in different ranges is a big determining factor of brightness and the physical location of notes in comparison to that range shapes our expectations of its brightness.

Answer 3

Many people experience keys with more sharps to be "brighter" and keys with more flats to be "darker," as this question discusses.

The accepted answer doesn't actually agree with the premise that a key with more sharps is brighter in and of itself - and while you may well be able to find a number of people who perceive things like that, I've not heard of any study that has found that any significant proportion of people do so (at least in an equal temperament context, which is normally what is assumed these days.)

Key signatures arrange themselves in a circle - so, for example, we can write a key signature that has the same actual pitches in (and the same octave-repeating pitches of tonic note) with 6 flats (G♭), or 6 sharps (F#). Could the very same piece, played on same set of note pitches, be simultaneously much brighter and much darker than itself? Simplistically speaking, no*.

Of course on a given instrument, there are many reasons why a given piece played in a different key may sound different - you'll have different resonances of the instrument (relative to the key), open strings and other 'unevenesses' in an instrument's topography will be in a different place(again, relatively), and we hear timbre differently at different pitches. But that shouldn't lead us to deduce that there's a general relationship between key signature and perceived level of brightness.

It's also possible that a given individual might perceive some keys as bright or dark relative to a key that they themselves are very familiar with (e.g. perhaps a pianist might see C major as neutral, and A major as brighter). But someone who has grown up with different pitch references would be expected to hear things differently; you wouldn't be able to deduce that people in general hear like our example pianist.

But does this quality of brightness/darkness also depend on the mode?

Again, simplistically speaking*, and for most people, I would say the perception of the feel of a piece only depends on the mode - and not on the given key signature, which is basically an accident of terminology that holds C major as special for historical, and not psychoacoustic, reasons.

---

*I say simplistically because mood of a piece is affected by timbre, timing, pitch inflections, intonation and temperament, and many other factors. And of course there are lots of other scales beyond the diatonic world of modes.

Answer 4

You ask about the brightness/darkness of modes from a particular key - all using exactly the same notes, but not in the right order (Eric Morecombe-ish).

For starters, bright and dark are somewhat subjective terms in themselves, so it's a difficult question made harder. Taking the Ionian as the basic mode, as is recognised today as the basic major, would generally be accepted as the brightest, as it's the major, and the one we hear most every day. Familiarity is a safe feeling, thus brighter rather than darker. Followed by the Mixolydian and Lydian, both of which contain the major third interval based on the root note.

A lot of people, in my experience, associate dark with serious, sombre, sad, staid, (and probably other words that begin with s...) so, the 'minor' modes will come over in that fashion - giving Dorian, Phrygian and Aeolian.

That leaves Locrian - one of the most difficult to play in, or listen to, so maybe that's the darkest of all.

Given that equal temperament is now de rigeur, I can't see how anything else factors in. Going back in time to earlier tuning systems, where an instrument such as harpsichord would be tuned to sound good in one key, I wonder if using modes from that key only would have the same darkness/brightness attributed to them. Somehow, I think nothing would be different. However, let's say that harpsichord is tuned to be good in D, then playing in D Dorian, D Phrygian, etc., would have a bigger difference, due to the tuning.

Or - have I missed the point entirely?