Saturday, February 21, 2009

Mode wrap-up (for now) and Locrian

To wrap up this segment on modes, I worked with the locrian.

Well...there certainly are issues here. Because there is no perfect fifth above the final (tonic), composers from the middle ages through the 19th century avoided it. Fux didn't cover it for the same reason: no P5 above the tonic = no way to have the fugal answer enter on the dominant.

The standard rotation of the scale to the fifth that I've been using all week to explore the other modes is useless here:

B C D E F G A B
F G A B C D E F

There aren't ANY intervals above the B that are matched above the F:

B-C = m2
F-G = M2

B-D = m3
F-A = M3

B-E = P5
F-B = A4

etc.



So -- though it may be interesting to try a canon at the tritone in locrian (and I may some day...), it doesn't fit with the method that I'm using (based on Fux) for the modal canon's of the last several days.

If we take the first, third and fifth degrees of the locrian, we get a diminished triad. Because this chord is made up of two stacked minor thirds, I tried that interval as the interval of imitation.

By aligning the pitches of the scale in thirds, I got this arrangement:

Tonic = B, third = D (half steps in bold)


D E F G A B C D
B C D E F G A B

Better results here. These intervals are the same above both the tonic (B) and third (D):

B - D = m3
D - F = m3

D - G = P4
B - E = P4

and below both:

D - C = M2
B - A = M2

So, unlike the other modes, there are no contiguous groups of notes/intervals that are usable under the restrictions that are imposed but we do have a "gapped" group of pitches:

(Tonic and third in bold)

A B ____ D E
C D ____ F G

An added benefit of this arrangement is that, if I emphasize the minor third (B - D) in the dux, the comes will answer with D - F and we'll hear the tritone B-F in close proximity.

(click on image to enlarge)


Disclaimer:

By the way, this is certainly NOT traditional. I tried to make it sound as traditional as possible but the composers of earlier times would not have written anything like this.

No comments:

Post a Comment