# Does a diminished unison really exist?

Hi!

When I teach my classes I tell them that there’s no such thing as a diminished unison (or “förminskad prim”, as we call it in Swedish). A perfect unison is the same note, and you can’t decrease the distance between it, only increase it.

But in Dorico I find that the term “diminished unison” is used to transpose a note half a step downwards. It should properly be called transposing a note an augmented unison downwards.

Or are there differing traditions regarding unisons?

I teach the same thing - if my students can actually create a diminished unison, then they have been able to decrease the size of nothing. If they can do that, then they really don’t need a degree in anything!

I also teach the same. It’s a fun trick question.

The theory professor of mine who first brought it up joked that if a diminished unison existed it would tear a hole in time and space.

If a diminished unison is played in the forest but no music theorist is there to hear it, does it still make a sound?

“The sound of one pitch flapping”?

If you transpose C by a diminished unison, you’ll get C flat, and if you transpose it by an augmented unison, you’ll get C sharp.

I don’t really understand that. I see that Dorico works this way, but I think the result is actually an augmented unison downwards, not a diminished unison.
The way the transpose dialog works for this is confusing to me — I’d rather ask it to transpose downwards by an augmented unison, rather than ask it to transpose by a diminished unison, which is an interval I don’t believe actually exists.

Is the key (no pun intended) to this the distinction between the interval itself, and actually transposing by the number of steps shared by that interval?

Just as you can add, say, ‘-5’ to any integer, positive or negative:

-5 + -5 is different from 5 + -5…

Diminished and augmented octaves definitely exist. (CPE Bach was very fond of diminished octaves).

So, what other name would you give to the (semitone) interval between C and C flat, to distinguish it from C to B?

(I suppose you could call it an “inverted augmented unison” )

An interval is a measure of distance - C to C# is a unison that has been made larger, i.e., the interval has been augmented; same if you go from C to Cb - the distance increased. They are both augmented unisons. You can’t diminish nothing, or put another way, you can’t reduce the number of half steps if you begin with 0.

Ok, off the high horse now.

As long as we know how Dorico thinks, then we can adjust accordingly.

Think of it like “negative harmony” (getting a lot of attention nowadays thanks to Jacob Collier).

I think this is exactly right. And Rob Tuley has it right also — the name for the interval we’re talking about it inverted augmented unison, or just an augmented unison down.

I sure hope there are no alien civilisations presently judging our species solely by studying this thread!

I think this only applies, if you believe a unison is 0.

I am sure there are some who wouldn’t think of a unison as 0.

Robby

Well, you may think I’m right, but I don’t. IMO that name is almost as sensible as defining every diatonic chord as an inversion of the Dominant 13th with most of the notes missing

If not 0, then what do you suggest? Set theorists certainly consider a perfect unison to be 0.

I think the question is whether you consider a diminished interval to be one semitone smaller than the regular interval, or one semitone closer to 0.
-1 is smaller than 0, but it is obviously further away from 0 than 0 is.

I’d hope they’d be fascinated, and approve. The stuff of debate .

It took a very long time before anybody was convinced that “0” was a number, and Europe was about the last place to “get it” as an idea, more than 1000 years after the Indians, ancient Egyptians and Babylonians, Chinese, Mayans, etc.

But we got there in the end - well, most of us did

This is exactly what I mean, only expressed a lot better.

Now I know how it works in Dorico, but it actually took me a couple of moments to figure it out, so in a perfect world this should be corrected in the program, but it’s no big deal!

Better be jugded by this thread than by a lot of “so sad” things going on nowadays.