I am taking my Gd 5 theory exam on 16th June and thought I was pretty much sorted for it. However, my teacher gave me some intervals to work out during my lesson at the weekend and I found them really hard.

I am finding it difficult to decide between minor and dimished.

Any help would be really helpful as I am starting to panic now!!


Thanks a million,

Ant

Minor is a semitone less than major.
Diminished is a semitone less than minor or perfect.

Think of it like a ladder:

Diminished on the bottom step, minor next step up, then major, and finally augmented for the top step (for intervals 2nd, 3rd, 6th and 7ths).

4ths, 5ths and 8ths have a smaller ladder with just diminished as the bottom step, perfect next step up and augmented as the top step.

OK - if you know your major scales then it's easy. All intervals in the major scale are either major or perfect. For example:

C-D = major 2nd
C-E = major 3rd
C-F = perfect 4th
C-G = perfect 5th
C-A = major 6th
C-B = major 7th
C-C = perfect octave

If a perfect interval is reduced by a semitone, then it becomes diminished.
If a major interval is reduced by a semitone, then it becomes minor. If it is further reduced by another semitone, then it becomes diminished.

So, discounted doubly diminished/augmented intervals for the moment, as they are not covered in Grade 5, you can have the following types of intervals:

diminished/minor/major/augmented 2nd
diminished/minor/major/augmented 3rd
diminished/perfect/augmented 4th
diminished/perfect/augmented 5th
diminished/minor/major/augmented 6th
diminished/minor/major/augmented 7th

If you don't know your major scales, then you need to tackle those. After that it just becomes Maths.