Okay...so the book I'm working in wants me to write a diminished 3rd below c#

The example

1) 3 below C# = A

2) A - C# = a major 3rd, they want a Dim. 3rd, so I have to make it 1 whole tone (2 semi tones) smaller

3) Raise A (nat) to A x to create a diminished 3rd below C#

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I'm EXTREMELY confused at the beginning of step 3

if you lower a a whole tone, doesn't that mean the note is G? but step 3 says it's A....

Someone explain?
Wouldn't they mean A to A#?
that would make the interval 1.5 instead of 2 tones.
Both of these are a 3rd, but in a diminished chord you'll use a 1.5-1.5-1 distance between notes.
I learned that in basic chord making (and those chords are based on the scales...) you get
M: 2-1.5 eg. A C# E
m: 1.5-2 eg A C E
dim: 1.5-1.5 eg A C D#
aug: 2-2 eg A C# F
And that kinda does make sense because in your situation, because if you'd use a regular scale, you'd never have 2 short 3rds after each other (never a 1.5-1.5 intervall possibility). So to create a diminished 3rd you'd have to shorten a 2-tone long 3rd to a 1.5-tone long one. In your question, you have the A-C# third in your scale as a 2-tone long one, and you wish to keep the C#. So you'd have to alter the A and make it an A#.
Major 3rd--2 whole steps, 4 semitones
Minor 3rd--1.5 whole steps, 3 semitones
Diminished 3rd--1 whole step, 2 semitones

Example use:
The scale:
E, F, Gb, A, B, C, D

As the Minor 3rd has been lowered by a half step, it is now a diminished third. While enharmonically equivalent to a Major 2nd, the diminished 3rd could be used to avoid having two 2nds in the scale.
Last edited by TheShred201 at Aug 26, 2008,
Quote by Swap-Meet
Okay...so the book I'm working in wants me to write a diminished 3rd below c#

The example

1) 3 below C# = A

2) A - C# = a major 3rd, they want a Dim. 3rd, so I have to make it 1 whole tone (2 semi tones) smaller

3) Raise A (nat) to A x to create a diminished 3rd below C#

-----------------------------------------------------------------------------------------------------------------

I'm EXTREMELY confused at the beginning of step 3

if you lower a a whole tone, doesn't that mean the note is G? but step 3 says it's A....

Someone explain?

they're trying to trick you... kinda

first of all, any kind of 3rd below any kind of C is an A

tutors set this kind of thing to see if you'll come out with a B or a G... enharmonically you might have the right note, but it has to be an A of some sort

a diminished 3rd is two semitones... so count down from C# two semitones... what note have you got?

B? WRONG! it's A## in other words A double-sharp... an A natural raised by TWO semitones

that little x in the book is the symbol for A##
out of here
A x is a doublesharp. Enharmonic to B.