#1
Hey everyone. I am starting to go through the CIG to Music Theory and was having a little bit of trouble in chapter 3 (yeah this book was made for me.) Anyways I had a few questions on diminished and augmented and flats and sharps for intervals. The questions are:

1. Is C to D a major 2nd interval?
2. Is B to C# a major 2nd?
3. Is B to C a minor 2nd?
4. Is D to F# a major 3rd?
5. Is D to G# a perfect 4th?
6. Is D to G a diminished 4th?
7. Is there such thing as a diminished or augmented octave or does it go by another name?

I think that's it for now but if you have anymore help please feel free to post it. Thanks.
#2
1. Is C to D a major 2nd interval? Yes.

2. Is B to C# a major 2nd? Yes.

3. Is B to C a minor 2nd? Yes.

4. Is D to F# a major 3rd? Yes.

5. Is D to G# a perfect 4th? No.

6. Is D to G a diminished 4th? No.

7. Is there such thing as a diminished or augmented octave or does it go by another name? Yes, there is such a thing as a diminished and augmented octave.


Edit: Reading your post again, I can't work out if you wanted me to answer them or not. That is what you wanted, right?
#3
yes that is what I wanted. thank you john. so then what is the answers to #5 and #6 then?
#4
Quote by Amped
yes that is what I wanted. thank you john. so then what is the answers to #5 and #6 then?


D to G# is an augmented fourth.
D to G is a perfect fourth.
#5
I am confused now because I thought that because there is no black key between E and F then it would have to make D to G# a perfect fourth because that would make it 6 half steps from D to G# which would make it a perfect fourth right? If D to F# is a major 3rd then doesn't D to G# have to be a perfect fourth? Thanks again.
#6
Quote by Amped
I am confused now because I thought that because there is no black key between E and F then it would have to make D to G# a perfect fourth because that would make it 6 half steps from D to G# which would make it a perfect fourth right? If D to F# is a major 3rd then doesn't D to G# have to be a perfect fourth? Thanks again.


The degrees are 1, b2, 2, b3, 3, 4, b5, 5, b6, 6, b7, 7, 1.

Six semitones (or three tones) is half the scale; a tritone, hence the #4/b5. D to F# is a major third; but after major third, it goes to perfect fourth. Hence, D to G would be a perfect fourth.
#7
Quote by Amped
I am confused now because I thought that because there is no black key between E and F then it would have to make D to G# a perfect fourth because that would make it 6 half steps from D to G# which would make it a perfect fourth right? If D to F# is a major 3rd then doesn't D to G# have to be a perfect fourth? Thanks again.


There is only a half step between a major third and perfect fourth.

If the major scale is constructed as WWHWWWH, starting on D - we get..


D + W = E
E + W = F#
F# + H = G
G + W = A
A + W = B
B + W = C#
C# + H = D

What we end up with...

[B]D Major Scale.[/B]

D - E - F# - G - A - B - C# - D.

D - Root.
E - Major second.
F# - Major third.
[B]G - Perfect fourth.[/B]
A - Perfect fifth.
B - Major sixth.
C# - Major seventh.


So, if G is our perfect fourth - adding one half step to G gives us G# - an augmented fourth.

6 half steps is half of one octave and would give you G# (an augmented fourth) or Ab (a diminished fifth). So, the distance from the root to the perfect fourth is only 5 half steps - whoever told you it was 6, was wrong.

Does that clear it up?