hello

need some brains .....I am working on intervals and would like to understand the following..

From an example of B to Aflat I work this out as follows.

(1) B - A sharp is major
(2) B - A is minor
(3) B - Aflat is diminished

If this is correct then I look at the major scale and sure enough (1) ok...but the same B - A sharp is in both harmonic and melodic scale.

My teacher says forget about major/minor and scales...(that's ok I can do that).

Please tell me if the above looks right and explain why it's called a minor interval why it does not fall into the minor scales notes.

I am assuming that we work the interval out from the lowest note and call it the tonic for the working out of the interval but in actual fact those notes could fall anywhere in a piece of music in any key.

If that is correct why do we call it a minor interval.....?

OK so the above may be all nonsense but that's how I understand it at the moment.

HELP

As far as minor 7ths go, the melodic minor contains both the sharpened 7th (on the way up) and the lowered (back to the key signature) 7th on the way down. So B-A natural is also an interval found in the minor scale. The raised 7th is a note 'borrowed' from the tonic major scale (B major in this exmple), thus giving a major seventh.

Clear as mud?

That looks right to me.. it's the way I would work it out.

A# in Bminor scale is an altered note... it's not in the key signature. A natural belongs to the natural minor scale with no altered notes.

You are right about always treating the lower note as tonic for the purpose of working out intervals and I always work them out by seeing how the notes relate to the major scale as you have done here.

Can't promise brains, but I'll do my best This works for non-perfect intervals...

Ignore minor scales for now

Look at the interval and give it a number - easy
Then, take the bottom note as tonic, and ask yourself "does the top note appear in the major scale?" If yes - easy, major. If it doesn't, it must be something else.

If it is a semitone up, it is augmented

If it is a semitone down, it is minor

If it is two semitones down it is diminished.

Your example looks right to me, and yes - that could fall into any piece of music in any key.

If you imagine the key sig of (your example) B minor - there's no A sharp or flat in it, so A natural is the minor note, you just only play it when you're coming down the melodic minor.

Hope that makes some sense!

The names of the intervals are based on some early theoretical ideas that are somewhat arbitrary, but the elaboration of them is logical.

The Mediaeval modes had initially six, later seven notes in them, the latter corresponding to the white notes on the piano. The theorists were concerned with the sounds of two notes played or sung together, and categorised such pairs as consonant or dissonant. The names and the intervals that corresponded to them were as follows:

Perfect consonance: . . unison (two voices singing the same note),
. . . . . . . . . . . . . . . . . . octave (e.g. C-c)
. . . . . . . . . . . . . . . . . . the fifths C-G, D-A, E-B, F-c, G-d, A-e
. . . . . . . . . . . . . . . . . . the fourths C-F, D-G, E-A, G-c, A-d, B-e

Imperfect consonance: thirds C-E, D-F, E-G, F-A, G-B, A-c, B-d
. . . . . . . . . . . . . . . . . . sixths C-A, D-B, E-c, F-d, G-e, A-f, B-g

Dissonance: . . . . . . . . seconds C-D, D-E, E-F, F-G, G-A, A-B, B-c
. . . . . . . . . . . . . . . . . . sevenths C-B, D-c, E-d, F-e, G-f, A-g, B-a
. . . . . . . . . . . . . . . . . . the fourth F-B (also known as the tritone)
. . . . . . . . . . . . . . . . . . the fifth B-f

The next stage was to realise that the consonant fourths all sounded similar, but differed from the tritone, which was larger. The consonant fourths were named "perfect fourths", and the larger one "augmented fourth". Similarly the consonant fifths were named "perfect fifths" and the smaller, dissonant one "diminished fifth".

Each of the seconds, and of the thirds, sixths and sevenths, came in two sizes, and none of these was perfect in Mediaeval harmony, so the larger intervals in each case were called "major", and the smaller "minor".

The major seconds are C-D, D-E, F-G, G-A, A-B; the minor ones are E-F, B-C.
The major thirds are C-E, F-A, G-B; the minor ones are D-F, E-G, A-c, B-d.
The major sixths are C-A, D-B, F-d, G-e; the minor ones are E-c, A-f, B-g.
The major sevenths are C-B, F-e; the minor ones are D-c, E-d, G-f, A-g, B-a.

Later, additional notes were added to the scale, at first to provide consonant fourths and fifths above notes that lacked them in the seven-note scale,* next to allow music in many keys and eventually to provide chromatic harmony. This produced more intervals to be named. For instance, the interval from E to Gb was clearly still a third, since F came between, but it was smaller than a minor third, so it was named "diminished third". Similarly, Gb to e was an augmented sixth, being larger than the major sixth from G to e.

* especially Bb above, below or after F, and F# above, below or after B, so as to avoid the tritone.