Use of “fixed” numbers?

Hello! In Sing The Numbers 2: Seven Worlds, I am wondering why the authors use a “fixed” number system for the 7 worlds. For example, the second harmonic environment (Dorian) starts with 2, third harmonic environment (Phrygian) starts with 3, etc. While I understand that Dorian starts on the second degree of Ionian, as it’s own harmonic environment, to me the tonic (root) should always be 1.

I find the current structure counterproductive and am not sure it is beneficial to use? Is STN 3 the same?

It would be good to have a moveable Do version of these products as to my ear naming the scale degree function makes the most sense. Barring moveable Do, I’d prefer the numbers start on 1 for each mode even though I understand that the numbers would have different functions based on which mode is being practiced.

Am I missing something?


Welcome to the forum @Wes37

I’m sure that @ImproviseForReal (David Reed) could provide a much better, & fuller, answer to your question, but I’ll have a go.

Do you have the IFR book?

I’m guessing maybe not?

Pretty much the whole idea behind Seven Worlds is based around the numbers remaining as they are, and seeing 2 as the ‘home’ for environment 2, 3 for environment 3, and so on.

IFR is a complete system in itself, not just classic music theory with different names, so IFR environments aren’t an exact equivalent of classic music theory modes.

Have you seen this youtube video by David Reed about how IFR harmonic environments & modes relates to each other?



Thank you for the response! I do have the IFR book, but I guess when reading the descriptions of using the numbers, I presumed that was more for theoretical reference as to the relationship between the seven worlds.

I’m still not sure I see the benefit of fixed numbers, though I am appreciative of the ideas in melody paths and other IFR ideas.


@Wes37 I was initially puzzled by harmonic environments as well. Here’s the things I came to realize that helped me…

  1. IFR is a system for improvising. When improvising you want to know by ear where you are and where you could go next, all in real time. You don’t want to do that intellectually, but by feel (by ear)

  2. IFR takes the tonal map (in numbers 1-7) as its main tool to do that. Everything is rooted in the tonal map. It tells you where you are and indicates where you can go. Best of all, there’s only a handful of fundamental things to learn to recognize by feel.

  3. To improvise you want a simple notation system that does the job, because you’re working in real time, and things keep moving by. But it’s true a variety of different notation systems could be used, each with different strengths and weaknesses, and appropriate for different jobs. By analogy, Roman Numerals are fine for naming numbers, but you wouldn’t want to use them for tasks that need multiplication or division. Computer professionals use numbers in base 2, 8, or 16, not base 10, because that’s handy for the kind of tasks they do. Scientific notation is handy for very large and very small measurements, but not so useful when balancing a checkbook. Bottom line is that different notation systems fit some jobs and don’t fit other jobs. There is no such thing as a perfect notation system.

  4. In a sense, the notation system doesn’t matter. What’s of primary importance is the sounds, not what we call them. You could play music completely by ear with no notation system at all, except when you want to remember tomorrow what you did today, or tell someone else about it. The map is not the territory.

  5. I think of a harmonic environment as the notes I could play at the moment, ordered from a temporary home base note, which tugs at the other notes. So The tune AUTUMN LEAVES starts by moving through the 2514 environments, a familiar progression that has its own overall sound.

But I’m still learning myself, so I’m sure I have holes in my understanding Hope this helps.


A pretty fundamental thing about IFR is that it’s very little about theory. It’s much much about playing & feeling the music & developing an understanding from that experience. The numbers & the harmonic environments are a way of trying to describe & annotate the experience, since if you are going to try to pass on ideas, especially in a book, you have to write something!

As @hender99 wrote, there are many annotation systems. None are perfect. When I found IFR I was already using moveable do solfege. It was okay but I can’t say I felt at home there. IFR numbers on the other hand made sense for me right away.

Similarly the Seven Worlds approach. In the moveable do solfege world I was already using the ‘la based minor’ idea & that is essentially the same approach as 6 being home in the 6th harmonic environment, so having 2 as home for the 2nd environment, etc., just felt like a natural extension.

Then when we start moving out of the simple basic environments & want chromatic notes, all we need to to add in IFR is a # or b. No need to introduce extra syllables as is done in solfege.

I know people who are very happy with solfege. That’s fine. We’re all different & different things work for different people. IFR numbers work for me.

Maybe give them a try for a while?


This is very helpful…thank you.

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I’ll give it a try and see…thank you for taking the time to explain.


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