Help me remember why some intervals are called major, minor, or perfect. I know all the basic stuff, but here's where I'm stuck: since a D above C appears in both the C major and C minor scale, how is the concept of a major vs minor 2nd interval explained in terms of a scale? Also, since a C up a half step to a D-flat is a minor 2nd, why isn't a C up to a G-flat a minor 5th? (rather than diminished?)

-- annie (noname_poster@yahoo.com), May 03, 2001

Answers

Annie, I'm going to try to answer this as intelligently as I can remember. A perfect interval (4th,5th,octave) cannot become minor. Example, a "minor 4th" is in reality a major 3rd, a "minor 5th" is a tritone, and a "minor 8th" is a major 7th. A major interval is based on the notes of the major scale ascending so a c major scale is C D E F G A B C. except for the perfect intervals all the others are major. The minor intervals then are all the other notes except for the tritone (diminished 5th or raised 4th) that divides the octave in half. Now, the true confusion is when you are descending, it's all backwards. From c down to Bb is a major 2nd, down to Ab is a major 3rd, etc. This is confusing for me because I think in terms of the scale rather than intervals, so I know that ascending C-B is a major interval, I want to think that descending C to B should be a major interval. Just wanted to make sure you are thoroughly confused!! ;-)

-- dlinder (dlinder@musician.org), May 06, 2001.

It's like this:

In any major or minor scale: a unison is perfect a 4th is perfect a 5th is perfect an octave is perfect

In a major scale: a 2nd is minor a 3rd is major a 6th is major a 7th is minor

In a minor scale: a 2nd is minor a 3rd is minor a 6th is minor a 7th is diminished

This changes with triads though. Like the mediant triad in a major key would be minor, but the mediant triad in a minor key is augmented.

-- theory (noname_poster@yahoo.com), May 07, 2001.

To identify an interval, the lowest note is regarded as the tonic of a major scale. A minor interval is a half tone smaller than a major. A diminished interval is a half tone smaller than a minor. An augmented interval is a half tone bigger than a major. A diminished interval is also a half tone smaller than a perfect interval and an augmented is a half tone bigger than a perfect.

-- Vipercat (noname_poster@yahoo.com), May 08, 2001.

Oh no, some of these answers are making me even more confused. One person said that in a major or minor scale, the 2nd is minor. Really? From C to D isn't considered a *major* 2nd? Then what's the interval from C to D-flat? I thought *that* was a minor 2nd. This person also said that in a major scale, the 7th is minor (I thought it was major) and that in a minor scale, the 7th is diminished (I thought it was minor) Hmmmm.....who is correct? Then someone else said a diminished interval is a half tone smaller than a minor. Well, only sometimes, right? From C to G-flat is a dim5, but that is not a half-tone smaller than a minor (it's a half-tone smaller than a major.) Not trying to be argumentative--just trying to figure out some things that I've never been clear on (and now some other things that I thought I was clear on, but perhaps wrong!)

-- annie (noname_poster@yahoo.com), May 09, 2001.

I also said that a half tone smaller than a perfect is a dimished. Therefore you are right, C-Gflat is a dim5 but it is a half tone smaller than a PERFECT not a major!

-- Vipercat (noname_poster@yahoo.com), May 10, 2001.

In addition, you are correct that C to D is a major 2nd.

-- Vipercat (noname_poster@yahoo.com), May 10, 2001.