Fretboard Evolution Vol. I - Steve Rieck

2. Any perfect or minor interval moved down a half-step and spelled with
the same alphabetical letters (ie: C to G moved to C to Gb or C to Eb
moved to C to Ebb …Yes – that’s a “double flat” which means down a
whole-step) is a DIMINISHED interval.
Like the rule above, some of these spellings can become a bit
ridiculous in practical use but do actually follow the same logic we
learned earlier in the chapter.
Like the perfect to perfect and major to minor inversions we saw above, you
might have already guessed that:
A DIMINISHED INTERVAL WILL ALWAYS INVERT TO AN AUGMENTED
INTERVAL AND VICE VERSA.
Below are some ascending intervals beginning on C. It’s important to explore
these concepts from other starting notes but for clarity, I think it’s good
to see it all from one note (in this case, “C”).
Notice all of the various enharmonic spellings and how the interval names
are different for each due to the actual letters involved.
C to C = Perfect Unison (same note)
C to C# = Augmented Unison (1 half-step)
C to Dbb = Diminished 2 nd (0 half-steps – enharmonic)
C to Db = Minor 2 nd (1 half-step)
C to D = Major 2 nd (2 half-steps)
C to D# = Augmented 2 nd (3 half-steps)
C to Ebb = Diminished 3 rd (2 half-steps)
C to Eb = Minor 3 rd (3 half-steps)
C to E = Major 3 rd (4 half-steps)
C to E# = Augmented 3 rd (5 half-steps)
C to Fb = Diminished 4 th (4 half-steps)
C to F = Perfect 4 th (5 half-steps)
C to F# = Augmented 4 th (6 half-steps)
© 2011 Steve Rieck – all rights reserved 39