PowerChromatic, Inverted Bebop, Diminished and all their relatives. A complete list!
Posted: Thu May 21, 2020 3:43 pm
When Brendan talks about his PowerChromatic tuning for diatonic half-valved harmonicas, there is a set of properties he often mentions as advantages:
* Each octave is the same
* Each draw two half steps above its blow note
* It has complete major scales through it's range, possibly with bends
(Of course there are many modes that are useful, but whenever I write "major scale" the other modes are implied.)
There are many tunings which are very useful without meeting these criteria, Easy 3rd for instance doesn't meet any of them, but for general purpose single-note playing I think it's a reasonable list.
Last summer, Patrick (IaNerd) Proposed the Inverted Bebop tuning, and Brendan noted that the IBB share all these properties of the PC. A while ago I started to ponder: What other such tunings are there?
I started a systematic search, and when considering shifted or transposed tunings as equivalent I ended up with what I found to be a surprisingly short list of tunings.
I'll limit the list to tunings with period four, as a shorter period can't meet the criteria, and a longer period reduces the range of the instrument.
So here we go!
Diminished: (Top row contains blow notes, bottom row draw notes. )
This well known tuning has all the requested properties. In fact, one could say it's sort of optimal since it can play ANY major scale.
I won't elaborate more on the dimi here, but for to point out what's probably its greatest weakness: Every key requires bends!
Let's add an additional criterion to the list: As many complete major scales as possible should be playable without bends.
As it turns out, no more than two tunings exist that meet this criterion with at least one complete scale without bends. They are:
Inverted Bebop:
PowerChromatic:
That's it! There are no other four-periodic tunings where draws are consistently one full step above their blows, which contain a complete major scale!
So far I've listed known tunings, but I have some news as well
Going through all possible combinations (henceforth accepting we'll have to use bends), I found that the PowerChromatic has two "sisters". I like to call them that, as the intervals between consecutive blow (or draw) notes are the same as for the PC (i.e. 2, 3, 4 and 3 half steps) but in different order; the three tunings are made from the only three possible permutations. In particular, the sisters are like PowerChromatic in that they have one note occurring twice.
One of them is obtained from raising both notes in either hole 2 or 3 (in the PowerChromatic tuning above) and the other by lowering the notes of hole 1 or 4, repeating this in every octave. I thus refer to them as the Sharp Sister and the Flat Sister, respectively.
Sharp Sister:
Flat Sister:
With bending, both PC sisters have the same set of playable notes as the PC and thus the same scales. The leftmost variations contain the same notes as the above out-laid PowerChromatic in G, so lacking any scale to name them for that's how I've named them for myself. (Any suggestions for another system are welcome)
I've seen snippets of the pattern of the Sharp Sister appearing as elements in some of Patrick's tunings, but never repeated for two periods or more:
viewtopic.php?f=9&t=212&start=60#p1665
viewtopic.php?f=9&t=212&start=40#p1578
viewtopic.php?f=9&t=212&start=40#p1591 (almost two periods!)
The pattern of the Flat sister I believe to be new.
Finally, there are three more repeating tunings that technically meet the criteria, but which probably are not very useful. At least not as general-purpose tunings. I include them for completeness. I call them the 1AKB, or the 1 Awkward Key Bastards, as each is capable of playing one single complete major scale using bends. They are capable of playing some pentatonic scales and blues scales, but much fewer than the previously listed tunings.
Here are the three tunings: (To highlight the awkwardness, I give them all in the key of C!)
That completes the list!
Summing up, there has been three known four periodic tunings with each draw note one full step above its blow note: the Diminished, the PowerChromatic and the Inverted Bebop. The new tunings I've introduced are the two sisters to the PowerChromatic, which might be useful, and the three 1 Awkward Key Bastards which might be less so. The complete lit thus spans exactly 8 tunings, or a mere 5 if we exclude the bastards.
After stumbling over this I found it interesting, so I thought some of you might find it so as well![Smile :)](./images/smilies/icon_e_smile.gif)
(I hope to elaborate a little on the new tunings in later posts, but as always there should be some considerable stress on the word 'hope'
)
* Each octave is the same
* Each draw two half steps above its blow note
* It has complete major scales through it's range, possibly with bends
(Of course there are many modes that are useful, but whenever I write "major scale" the other modes are implied.)
There are many tunings which are very useful without meeting these criteria, Easy 3rd for instance doesn't meet any of them, but for general purpose single-note playing I think it's a reasonable list.
Last summer, Patrick (IaNerd) Proposed the Inverted Bebop tuning, and Brendan noted that the IBB share all these properties of the PC. A while ago I started to ponder: What other such tunings are there?
I started a systematic search, and when considering shifted or transposed tunings as equivalent I ended up with what I found to be a surprisingly short list of tunings.
I'll limit the list to tunings with period four, as a shorter period can't meet the criteria, and a longer period reduces the range of the instrument.
So here we go!
Diminished: (Top row contains blow notes, bottom row draw notes. )
Code: Select all
c d# f# a c d# f# a
d f g# b d f g# b
I won't elaborate more on the dimi here, but for to point out what's probably its greatest weakness: Every key requires bends!
Let's add an additional criterion to the list: As many complete major scales as possible should be playable without bends.
As it turns out, no more than two tunings exist that meet this criterion with at least one complete scale without bends. They are:
Inverted Bebop:
Code: Select all
g b c e g b c e
a c# d f# a c# d f#
Code: Select all
g a c e g a c e
a b d f# a b d f#
So far I've listed known tunings, but I have some news as well
![Smile :)](./images/smilies/icon_e_smile.gif)
Going through all possible combinations (henceforth accepting we'll have to use bends), I found that the PowerChromatic has two "sisters". I like to call them that, as the intervals between consecutive blow (or draw) notes are the same as for the PC (i.e. 2, 3, 4 and 3 half steps) but in different order; the three tunings are made from the only three possible permutations. In particular, the sisters are like PowerChromatic in that they have one note occurring twice.
One of them is obtained from raising both notes in either hole 2 or 3 (in the PowerChromatic tuning above) and the other by lowering the notes of hole 1 or 4, repeating this in every octave. I thus refer to them as the Sharp Sister and the Flat Sister, respectively.
Sharp Sister:
Code: Select all
g bb c e g bb c e (or g a c# e g a c# e
a c d f# a c d f# a b d# f# a b d# f#)
Code: Select all
f# a c e f# a c e (or g a c eb g a c eb
g# b d f# g# b d f# a b d f a b d f)
I've seen snippets of the pattern of the Sharp Sister appearing as elements in some of Patrick's tunings, but never repeated for two periods or more:
viewtopic.php?f=9&t=212&start=60#p1665
viewtopic.php?f=9&t=212&start=40#p1578
viewtopic.php?f=9&t=212&start=40#p1591 (almost two periods!)
The pattern of the Flat sister I believe to be new.
Finally, there are three more repeating tunings that technically meet the criteria, but which probably are not very useful. At least not as general-purpose tunings. I include them for completeness. I call them the 1AKB, or the 1 Awkward Key Bastards, as each is capable of playing one single complete major scale using bends. They are capable of playing some pentatonic scales and blues scales, but much fewer than the previously listed tunings.
Here are the three tunings: (To highlight the awkwardness, I give them all in the key of C!)
Code: Select all
b c# d# g b c# d# g
c# d# f a c# d# f a
b d eb g b d eb g
c# e f a c# e f a
c eb g b c eb g b
d f a c# d f a c#
Summing up, there has been three known four periodic tunings with each draw note one full step above its blow note: the Diminished, the PowerChromatic and the Inverted Bebop. The new tunings I've introduced are the two sisters to the PowerChromatic, which might be useful, and the three 1 Awkward Key Bastards which might be less so. The complete lit thus spans exactly 8 tunings, or a mere 5 if we exclude the bastards.
After stumbling over this I found it interesting, so I thought some of you might find it so as well
![Smile :)](./images/smilies/icon_e_smile.gif)
(I hope to elaborate a little on the new tunings in later posts, but as always there should be some considerable stress on the word 'hope'
![Wink ;)](./images/smilies/icon_e_wink.gif)