In the previous post I summarized a voicing that sounded good.

Today, I recognized that I had in a way re-invented the wheel. I had been thinking of this voicing as:

  • start on any 7th chord tone as the lowest voice and proceed up
  • skip one chord tone
  • add two chord tones in order
  • add the skipped chord tone

Well, here’s another way to think about this voicing — as always in music, symmetries abound:

  • start on any 7th chord tone and proceed down
  • skip one chord tone
  • add two chord tones in order
  • add the skipped chord tone

Both of these algorithms arrive at the same result. The difference is that the latter has a common name: the so-called Drop-2 Voicing. “2” because it’s the second voice from the top and “drop” because it is dropped an octave. Fair enough. I might still continue to think of it in my system, because it’s more interesting to think of what the chord is built on top of.

2-5-1 “Drop 2” Voicings

In each of the algorithms above, which both arrive at the same result, we can start on any chord tone. There are 4 chord tones in a 7th chord. The one for “Third in the bass” is reproduced from the previous post, except I’ve removed the b9 from the V, so as to accentuate the symmetries in voice leading. I’ll also generalize and use a generic ii chord — i.e. not calling out a specific b5, because the voicing pattern can be generalized to 2-5-1s of any quality.

Arrows (-->) indicate pitch changes.

Symmetries abound

Note as always that when going round the circle of fifths:

  • 1 becomes 5; 5 becomes 1.
  • 3 becomes 7; 7 becomes 3.

In the smoothest voice leading:

  1. One voice from each pair (i.e. 1 and 5 and 3 and 7) moves down, while the other stays.
  2. Then, the voices that have just moved stay. The other voices move down.

Root in the bass

Voices 
S     3       7 ----> 3
A     7 ----> 3       7
T     5 ----> 1       5
B     1       5 ----> 1

     ii       V       I
Intervals 
4       5       4
3       3       3
5       4       5


ii      V       I

Third in the bass

Voices 
S     5 ----> 1       5
A     1       5 ----> 1
T     7 ----> 3       7
B     3       7 ----> 3

     ii       V       I
Intervals 
5       4       5
2       3       2
5       4       5


ii      V       I

Fifth in the bass

Voices 
S     7 ----> 3       7
A     3       7 ----> 3
T     1       5 ----> 1
B     5 ----> 1       5

     ii       V       I
Intervals 
5       4       5
3       3       3
4       5       4


ii      V       I

Seventh in the bass

Voices 
S     1       5 ----> 1
A     5 ----> 1       5
T     3       7 ----> 3
B     7 ----> 3       7

     ii       V       I
Intervals 
4       5       4
3       2       3
4       5       4


ii      V       I