Multiple sources of background noise "harmonizing" -- who's studied this, and what did they find?

April 9, 2009 8:38 AM

Heard an NPR story 7(ish) years ago about a guy who measures the pitch of various sources of barely-audible workspace/home background noise (eg. harddrive spinning, refrigerator compressor running, and the flyback transformer on your television) and seeing what chords they made. He contested that different chords would affect peoples' productivity, attitudes, etc. I have some questions about this.

I remember it being a bit suspect -- the guy was making a living off of this -- but he was pretty modest in his claims and spoke eloquently about it. Even though it didn't make me an out-and-out believer, it made me think quite a bit about it. He was consulting various companies and offering to "tune" office background noise, claiming that it would have an effect on worker happiness. (I remember him claiming that "minor chords make people edgy".)

But the thing I'm REALLY curious about was this tangent he went on when describing his research. I remember him referencing some, like, 16th century monk (or somesuch, not sure on dates) who wrote VERY long treatises on these VERY specific emotional responses to specific chords; going so far as to say things along the lines of "B flat Major: Wistful longing with a bright, hopeful blah blah blah..." It was presented as though it was this monk's life's work/personal obsession. (I'm thinking that he was projecting a bit and probably barking up the wrong tree, but it was pretty fascinating.)

First off: anyone know who this guy is (and/or other folks who have researched similar things?). Secondly: anyone know anything about the monk he mentioned or anyone who's attempted any sort of similar... stuff? I'm not very music-theory-fluent, but I'm willing to read challenging things... Thanks a ton.

Here's where I'll make the obligatory Spinal Tap reference about D minor being the "saddest of all keys", just to get it out of the way...

posted by cadastral to Media & Arts (14 answers total)

This page has what you're looking for. The emotions tended to be assigned to key signatures rather than chords, though.

Many theoretical works of the eighteenth century explicitly assign certain affectations or emotional characteristics to different keys. Though these writings often contradict each other as to what these characteristics actually are, it is well known that many composers carefully chose keys for similar affectations throughout their lives.

Note that before the adoption of our modern system of equal temperament, different keys really did sound different. On a modern piano, however, they all sound the same.
posted by ludwig_van at 8:44 AM on April 9, 2009

By the way, that was on the first page of google results for "music key signature emotion."
posted by ludwig_van at 8:46 AM on April 9, 2009

I am almost certain that I heard that very story on This American Life. The original may have been old, but I downloaded it sometime last year so they may have repeated it. You might search through their archived podcasts, perhaps, if you wanted to hear the story again.
posted by DrGirlfriend at 8:55 AM on April 9, 2009

You might be thinking of This American Life, Episode 110. "TAL contributor Jack Hitt visits Toby Lester, who has mapped all the ambient sounds in his world: the hum of the heater, the fan on the computer."

I don't remember the guy making a living from this, but it's worth a look.
posted by kidbritish at 9:06 AM on April 9, 2009 [3 favorites]

Sorry for possible derail, but ludwig_van, can you explain how equal temperament makes all keys sound the same? I know it changes the structure of the scale, but the notion that different keys sound different (and have different psychological effects) is based on the difference in the tonics, isn't it? Or are you referring to differences in scales (not keys)?
posted by bricoleur at 9:35 AM on April 9, 2009

*makes note to self to inform best friend with perfict pitch of new career option*
posted by iceprincess324 at 9:44 AM on April 9, 2009

bricoleur: I am not sure what you are getting at with your scale/key distinction. I think ludwig_van is referring to the fact that a different key signature would have a different series of ratios between notes, pre equal temperament, since the half and whole step would be different ratios for different notes in each scale, We are effected very little by the specific frequencies of a sound, but we are effected significantly by the ratios between the frequencies.
posted by idiopath at 11:36 AM on April 9, 2009

idiopath, that's what I'm getting at. I think there is some confusion here between scales, keys, and, perhaps, modes.

the half and whole step would be different ratios for different notes in each scale

--this is true if you really do mean "scales" and not "keys." It is not true if you mean different keys in just temperament. In just temperament (i.e., before equal temperament), the ratio between the frequencies of the tonic and the fifth in any key is the same. Likewise the tonic and any other note. In other words, you merely move the whole structure of ratios up or down a certain number of half steps; you do not change the structure itself. If you were (also) to change the structure, it would result in more than a change of key—it would mean either a change of mode, or, in a more extreme case, a new scale (i.e., a new way of dividing the octave) altogether. Different musical cultures have chosen different sets of ratios to divide the octave—as an example, think of gamelan. That's what I meant by "scale," though admittedly the word is ambiguous in this context.

All equal temperament does is fudge the (canonical Western) ratios in a way that allows you to change keys without things getting out of whack (google "circle of fifths" for the verbose explanation).
posted by bricoleur at 12:08 PM on April 9, 2009

Idiopath is right regarding equal temperment. It is a compromise that standardizes the intervallic structure (the distance from note to note in a given scale). Here is a past thread over in Metafilter Music that touches on the topic.

I haven't listened to the episode, but based on your description of it, I am skeptical. That is, if he really is suggesting that certain chords, unmediated by cultural factors, cause specific emotional responses. Just because a monk said it in the 16th century doesn't make it universally so. A fan of noise music or death metal or whatever strident genre could potentially be relaxed and fall asleep to the stuff, while it could traumatize someone else. That is, within a reasonable volume range--if it is piercingly loud, there is a threshold where anyone would panic. But specific harmonies?
posted by umbú at 12:15 PM on April 9, 2009

In just temperament (i.e., before equal temperament), the ratio between the frequencies of the tonic and the fifth in any key is the same.

But it's not possible to have just temperament for all keys on the same instrument, right? Which is what I think you're getting at here:

All equal temperament does is fudge the (canonical Western) ratios in a way that allows you to change keys without things getting out of whack (google "circle of fifths" for the verbose explanation).

So if you have a keyboard that's tuned to just temperament for the key of C, a C major chord is going to sound very different from an F# major chord, where on an equal-tempered piano they will sound basically the same.
posted by ludwig_van at 12:55 PM on April 9, 2009

And by "instrument" I mean "instrument of pre-defined pitch," like a keyboard or guitar. Other kinds of instruments obviously have more flexibility.
posted by ludwig_van at 12:56 PM on April 9, 2009

So if you have a keyboard that's tuned to just temperament for the key of C, a C major chord is going to sound very different from an F# major chord, where on an equal-tempered piano they will sound basically the same.

Thanks for the clarification, ludwig_van; I see what you meant now.

I was mentally moving from a (fixed-pitch) instrument tuned in just intonation to one key, to another instrument tuned to the other key. That's what I meant, though perhaps did not express clearly, when I said, "if you mean different keys in just temperament."

If you do that—which, I had thought, was what people generally did when they wanted to change keys before equal temperament, because the results are discordant otherwise—then one key does sound the same as another. But if you try to change keys on the same fixed-pitch instrument tuned to just intonation, then yes, as you say, you do get different sounding keys.
posted by bricoleur at 1:33 PM on April 9, 2009

Right. But of course key was often somewhat fluid, even in the common practice period -- a piece in C major might modulate to several other keys, or failing that it will at minimum borrow chords from outside of the key signature. And having 12 different harpsichords on hand was obviously impractical.

The limitations of older instruments come into play in other ways, too. For instance, the key of D major is often described in these treatises as "martial" or "war-like." This is in part because trumpets and other brass instruments were commonly used by armies in order to communicate on the battlefield. Before the relatively recent incorporation of valves, there were natural trumpets, which could only play in one key. These trumpets were often in the key of D, hence the description of D major as being a war-like key.
posted by ludwig_van at 7:53 PM on April 9, 2009

The idea that different musical intervals have different emotional impacts dates back to Plato and the Greeks. Back then there were no "keys" as we think of them, but there were musical modes. Plato actually believed that some modes could encourage moral behavior, while others were downright subversive.

Like a lot of classical concepts, this idea got revived in the Renaissance by a whole slew of music theorists, but obviously they had no recordings to base their theories off of, so much of the theory had to be invented anew. My best bet for the "monk" you're thinking of is Glarean, though Tinctoris, Zarlino, Vincenzo Galilei and Nicola Vicentino are also likely candidates.

Most of these guys were not "monks" strictly speaking, but since churches were the center of most scholarly musical activity at the time, most music scholars (composers, theorists, etc.) held down positions in the church that were at least nominally theological at one time or another.

Since this was the 16th century, this still predates equal temperament and "keys" as we know it. They wouldn't think in terms of "B-flat major," for example, but in terms of modes like "Dorian" or "Lydian," etc. If it really is a 16th century monk you're thinking of, he would definitely be talking about modes, not keys. He may have talked about chords and intervals, though (which is why I think it's probably Glarean or Zarlino, because they wrote about chords and intervals if I recall correctly).
posted by speicus at 1:49 AM on April 10, 2009