JohnPic

John O'Sullivan

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Eagle 53 Musical Tuning
 
Eagle 53 is a 12 notes per octave tuning designed to improve on, and replace,
the standard Western tuning: 12 Tone Equal Temperament. Some notes are higher
than usual and others are lower in varying degrees (see the frets in the photo
below). Eagle 53 has many advantages over the standard tuning
(12 Tone Equal Temperament).
Many chords are more in tune and many new and exotic scales and chords occur
that you won't find in 12 Tone Equal Temperament.
The "53" refers to 53EDO (53 Equal Divisions of the Octave). Eagle 53 is
a 12 note subset of 53EDO or 53 Tone Equal Temperament.

Eagle 53 Guitar

E53fretboarddiagram

Click here to hear Atonement to a Centaur by Chris Vaisvil
in Blue Just Intonation which is similar to Eagle JI

Click here to see a video of me playing Hear My Train a Comin'
by Jimi Hendrix on my Eagle 53 guitar

Click here to launch an app that plays seven strong and
beatless chords in Eagle 53 whose root notes
correspond to 3:4:5:6:7:8:9
 
Click here for a 10 strong chords Eagle 53 app

Click here for a 35 chords Eagle 53 app

Click here for a brief article on how I arrived at
my Eagle 53 musical tuning

Click here for strongly rooted chord progressions in Eagle 53

Click here for Eagle 53 demo tune Uccellini

Click here for Eagle 53 demo tune Bach

Click here to launch an app that demonstrates what can
be done in 19 Equal Divisions of the Octave.

Click here to launch an app that demonstrates the
Hijaz Kar (Arabian) scale in Eagle 53.

Click here to see a video of me playing some major chords on
my Eagle 53 guitar (E, G, A, B, C, D, E)

Click here to hear a short interlude for clavichord in Eagle 53
by Chris Vaisvil.

Click here to hear John's Tune in Blue JI which is similar
to Eagle JI.

Click here for an essay on 24EDO (Middle Eastern flavour music)

Beatless Chords document


On Eagle 53 guitars (tuned EADGBE) the E major, E minor, F major, G major, G# minor, A major, A minor,
B major, B minor, C major, C# minor, and D# minor are all good and are more in tune than in
standard tuning (12 Tone Equal Temperament). There is a 4:5:8:10 chord available on
F# (F#,A#, F#,A#) and on D (D, F#, D,F#).
All of these chords are all within 1.41 cents accuracy of just (pure), almost perfectly in tune.
A major chord looks like 2:3:4:5:6:8. A minor chord looks like 10:15:20:24:30:40

Check out my Eagle Tuning group on Facebook...
www.facebook.com/groups/eagletuning


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Here is my "Ultimate Tuning" book. The book describes how
I arrived at my Eagle 53 tuning, the rationale and
the mathematics behind it.
Click here for a review of the book by
Declan Clark (AKA Xotla)
MUMTcov2

Click here for a free PDF of the book

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My take on Just Intonation. Click here to download it.

JohnsJIcover


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This book describes over a dozen strong chord progressions
that occur in the Eagle 53 tuning.
Click here for the free PDF.

Strong Progs Cover
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This book is about my Swan Scale which is a subset of my
Eagle 53 Musical Tuning. It is aimed at players of piano or similar
keyboard instruments. *Any* chord progression using any of
the 2,002 strict/jazz chords listed should be good.

SwanCoverTest2
Click here for a free PDF of the book

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 This book is about beatless chords on lutes that are fretted
according to my Eagle 53 tuning. There is also a treatise
on 19EDO which is currently available free (see
Nineteen Equal Divisions of the Octave below).
The book is very short, 58 pages.

Lutes Cover



Click here for a free PDF of the book
 
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 My book about the Arabian Scale in Eagle 53. 507 chords are
listed that belong to the Arabian 'melodic base'. These are
for Eagle 53 fretted guitars and keyboards tuned to
Eagle 53. Any and all chord progressions should
be good if you stick to the chords listed.
The book is a 'proof of concept'.
1/1, 16/15, 5/4, 4/3, 3/2, 8/5, 15/8, 2/1
E, F, G#, A, B, C, D#,E

Click here to launch my Arabian scale web app.
Click here for a free PDF of the book.
Arabian Cover

 
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19EDO cover

Click here to download a free PDF of my treatise on
Nineteen Equal Divisions of the Octave.

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My book for piano or keyboard players. 2,770 strong
chords and 96 scales are listed. There is also a chapter
on composing in Eagle 53. This is for keyboards
tuned to the Eagle 53 tuning.

Pianist cover


Click here for a free PDF of the book

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Eagle 53 Jazz Chords is a sequel to the Eagle 53 Pianist.
2,999 chords are listed in this book. These are not as
strong as the chords in the Pianist book but are
very versatile in the right context. There is
some new compositional theory as well.

Jazz Cover


Click here for a free PDF of the book

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Here is my book which describes my rules for musical
composition, chords and chord progressions and
melodies, especially using alternative tunings.
This book has only 20 pages of text. The other 80
pages list 96 scales and 2196 "legal" intervals.
Click here for a free PDF of the book.

JRM cover


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Here is my Guitarist book which contains 940 diagrams
of lush chords and 96 scales for Eagle 53 guitars. Lush
chords are both strong and clearly rooted. 96 scales are
also listed. Note that Eagle 53 cannot be implemented
on regular guitars, a special fret arrangement is required.
There is a chapter on composing in Eagle 53.

Guitar Lush Cover

Click here for a free PDF of the book

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This book is a sequel, or companion, to The Eagle 53
Guitarist Lush Chords. The book describes 823
chords that are not "lush" but are very versatile
in  the right context.

Guitar Jazz Cover

Click here for a free PDF of the book

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 Eagle 53 in cents...
0.0, 113.2075, 203.7736, 316.9811, 384.9057, 498.1132, 588.6792,
701.8868, 815.0943, 883.0189, 1018.8679, 1086.7925, 1200.0

Eagle 53 is a tempered version (a subset of 53EDO) of the following just scale...
1/1, 16/15, 9/8, 6/5, 5/4, 4/3, 7/5, 3/2, 8/5, 5/3, 9/5, 15/8, 2/1

I arrived at this tuning on 22nd June, 2016 with the help of Jake Freivald.
It is not clear to me whether this tuning is new or not.

The following chords  occur in Eagle 53…
This is just a sample, there are 1,763 chord diagrams in my Guitarist books (see above)
and around 4,770 chords are listed in my Pianist books (see above).

               E (1/1) Major 2:3:4:5:6:8____________E, B, E, G#, B, E
                 E (1/1) Minor 10:12:15:20:24:30:40___E, G, B, E, G, B, E
  E (1/1) Power Chord 2:3:4:6________E, B, E, B
        E (1/1) Power Chord 4:5:8:10_______E, G#, E, G#
            F (16/15) Major 2:3:4:5:6:8__________F, C, F, A, C, F
  F (16/15) Power Chord 2:3:4:6______F, C, F, C
  F (16/15) Power Chord 4:5:8:10_____F, A, F, A
       F (16/15) 7 limit Chord 2:3:4:5:7____F, C, F, A, D#
                 F# (9/8) 15:20:30:40:48:60__________F#, B, F#, B, D, F#
            F# (9/8) Power Chord 4:5:8:10______F#, A#, F#, A#
             G (6/5) Major 2:3:4:5:6:8___________G, D, G, B, D, G
   G (6/5) Power Chord 2:3:4:6_______G, D, G, D
  G (6/5) Power Chord 4:5:8:10______G, B, G, B
            G# (6/5) 9 limit chord 4:6:8:9______G#, D#, G#, A#
                             G# (5/4) Minor 10:12:15:20:24:30:40_G#, B, D#, G#, B, D#, G#
            G# (5/4) Power Chord. 2:3:4:6_____G#, D#, G#, D#
               A (4/3) Major 2:3:4:5:6:8___________A, E, A, C#, E, A
                 A (4/3) Minor 10:12:15:20:24:30:40__A, C, E, A, C, E, A
  A (4/3) Power Chord 2:3:4:6_______A, E, A, E
       A (4/3) Power Chord 4:5:8:10______A, C#, A, C#
     A# (7/5) 7 limit chord 7:10:14:20___A#, E, A#, E
                         A# (7/5) 15:20:30:40:48:60_________A#, D#, A#, D#, F#, A#
               B (3/2) Major 2:3:4:5:6:8___________B, F#, B, D#, F#, B
                 B (3/2) Minor 10:12:15:20:24:30:40__B, D, F#, B, D, F#, B
  B (3/2) Power Chord 2:3:4:6_______B, F#, B, F#
    B (3/2) Power Chord 4:5:8:10______B, D#, B, D#
          C (8/5) Major 2:3:4:5:6:8___________C, G, C, E, G, C
C (8/5) Power Chord 2:3:4:6_______C, G, C, G
C (8/5) Power Chord 4:5:8:10______C, E, C, E 
        C (8/5) 7 limit Chord 2:3:4:5:7______C, G, C, E, A#
                          C# (5/3) 9 limit chord 3:4:6:8:9:12___G#, C#, G#, C#, D#, G#
(4 or C# is the root note of the chord)
                          C# (5/3) Minor 10:12:15:20:24:30:40_C#, E, G#, C#, E, G#, C#
         C# (5/3) Power Chord   2:3:4:6_____C#, G#, C#, G#
   D (9/5) Power chord 2:4:5:8________D, D, F#, D
   D (9/5) Power Chord 4:5:8:10______D, F#, D, F#
 D (9/5) D+ (D plus) 6:10:12:15______D, B, D, F#
                                 D# (15/8) Minor 10:12:15:20:24:30:40_D#, F#, A#, D#, F#, A#, D#
           D# (15/8) Power Chord  2:3:4:6_____D#, A#, D#, A#
           D# (15/8) Power chord 3:4:6:8______A#, D#, A#, D#
(4 or D# is the root note of the chord)

All of the intervals in all of these chords (except for the 7 and 9 limit chords)
are within 1.41 cents of just in Eagle 53.
The seven limit chords are all within 6.2 cents of just.
The nine limit chords are within 3.9 cents of just.
          There are thousands more.            

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FOR LUTHIERS...

Here is a diagram of an Eagle 53 guitar fretboard

Eagle 53 guitar fretboard

For luthiers, click here to download free specifications for fret placements for Eagle 53 guitars.

Click here for a diagram of my Eagle 53 fretboard.

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Chris Vaisvil's' web site: http://www.chrisvaisvil.com

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A picture of an NPT guitar should appear here.
Click here to hear a tune I wrote using the "Blue Just Tuning" guitar shown above. I ripped the frets out of a standard guitar and replaced them with new frets in different positions.

The tune is called "John's Tune".

Use your sound control panel to shift the balance fully to the left (to hear the chords only) or shift the balance fully to the right (to hear the lead only).


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Here's a book cover I designed (but didn't use) for my first book which was
published around 2010. The fretboard on the right corresponds to my
Blue Just Tuning if I remember correctly.


Cover of The Mathematics of Music



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The Zen Scale
0c - 100c - 250c - 350c - 550c - 700c - 850c - 1050c - 1200c
1/1 - 17/16 - 15/13 - 11/9 - 11/8 - 3/2 - 18/11 - 11/6 - 2/1
This scale is about as "Xenharmonic" (unusual) as you can get.
Click here for a list of 2:3:4:6 power chords
where the root notes of the chords
conform to The Zen Scale.
Click here for an app that demonstrates The Zen Scale.

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CONTACT:  jfos777@yahoo.com

John O'Sullivan

9th April 2026



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