LCC Interval Categories Chart aka Tonal Gravity Chart
Posted: Sun Sep 20, 2009 11:15 am
Here is the chart I have for the Interval Categories. This is the chart we have been referring to as the "Tonal Gravity" chart.
We have copies here on the forum of the 1950's version, but this is a version that was started in the 70s and had some edits made to it later.
This version is updated through 1993 or 1994.
http://www.4shared.com/file/134064594/6 ... 1990s.html
Can anyone shed light on how this chart was derived?
This chart does not seem to be generated in the same fashion as the 1959 version, which uses the ladder of fifths in intersection with Lyd, then Lyd Aug, then Lyd Dim, then the 9 TO scale, etc..
We expect some differences in that the new edition of the LCC changes the b7 to the 10 TO and the 4th to the 11 TO.
But there are other differences in addition to that.
For example, in the min 2nd category, in the 9TO, we have listed minor seconds on:
+5
b3
5
2
+5 makes sense because Lyd Aug is the first scale in the 9TO. But why is b3 listed next, which comes from the 9TO composite scale? Why not the 2, which comes from the Lyd Dim? If I am not mistaken, the 1959 instructions use the 9TO after the LA and LD scales are used.
If all the intervals simply come from the 9TO as a whole, what specifies their order?
I thought at first that the intervals might have been chosen by the consonance of the tonic of each of the intervals within the LCS. For example:
The tonic of a stand-alone min 2nd interval is the top note. Thus the tonic of a min 2nd on +5 in C would be A, the tonic of the b3 interval would be E, the tonic on 5 would be Ab and the tonic on D would be Eb.
If we grade the tonics of these intervals: A, E, Ab, Eb in order of consonance, we get the order given on the chart.
However, the 10TO minor 2nds category lists:
6
b7
By the same logic, the tonic of the min 2nd on 6 would be Bb, and the tonic on b7 would be B.
And Bb doesn't come before B in terms of consonance.
Any help would be appreciated!
We have copies here on the forum of the 1950's version, but this is a version that was started in the 70s and had some edits made to it later.
This version is updated through 1993 or 1994.
http://www.4shared.com/file/134064594/6 ... 1990s.html
Can anyone shed light on how this chart was derived?
This chart does not seem to be generated in the same fashion as the 1959 version, which uses the ladder of fifths in intersection with Lyd, then Lyd Aug, then Lyd Dim, then the 9 TO scale, etc..
We expect some differences in that the new edition of the LCC changes the b7 to the 10 TO and the 4th to the 11 TO.
But there are other differences in addition to that.
For example, in the min 2nd category, in the 9TO, we have listed minor seconds on:
+5
b3
5
2
+5 makes sense because Lyd Aug is the first scale in the 9TO. But why is b3 listed next, which comes from the 9TO composite scale? Why not the 2, which comes from the Lyd Dim? If I am not mistaken, the 1959 instructions use the 9TO after the LA and LD scales are used.
If all the intervals simply come from the 9TO as a whole, what specifies their order?
I thought at first that the intervals might have been chosen by the consonance of the tonic of each of the intervals within the LCS. For example:
The tonic of a stand-alone min 2nd interval is the top note. Thus the tonic of a min 2nd on +5 in C would be A, the tonic of the b3 interval would be E, the tonic on 5 would be Ab and the tonic on D would be Eb.
If we grade the tonics of these intervals: A, E, Ab, Eb in order of consonance, we get the order given on the chart.
However, the 10TO minor 2nds category lists:
6
b7
By the same logic, the tonic of the min 2nd on 6 would be Bb, and the tonic on b7 would be B.
And Bb doesn't come before B in terms of consonance.
Any help would be appreciated!