Question: How can I distinguish minor from major pitches?
Albert's reply: Major and minor aren't properties of single notes or pitches but rather of groups of notes. Major and minor can refer to keys, scales, chords and intervals. Let's look at them in turn.
The key of a piece or passage is determined by its scale. Generally speaking, if a section of music is built predominantly on the scale of C major, then that section is in C major. (There are exceptions, such as modal music and modulatory passages—and it's possible for the key of a passage of music to contradict its key signature. However, I wish to speak only of basics for the purpose of this lesson.)
Every major scale has a corresponding relative minor, and vice versa. Relative keys share the same key-signature. Given a key signature in a piece of music, how can you tell whether it indicates major or minor? I wrote a lesson titled Major and Minor Keys in which I explain how to distinguish these two modes.
It's easy to distinguish a major chord from a minor one. For this lesson I'll limit chords to triads, which consist of three notes, each a third removed from the last.
A major triad consists of a major third plus a minor third built on top of it. For example, a C major triad (C major chord) consists of the notes C, E and G. The interval from C to E is a major third, and the interval from E to G is a minor third.
A minor triad is just the reverse: a minor triad plus a major triad on top of it. A C minor triad (C minor chord) consists of the notes C, E-flat and G. The interval from C to E-flat is a minor third, and the interval from E-flat to G is a major third.
You should also learn to recognize major and minor triads by ear.
Major and minor intervals are another story, and they are more complex. Only seconds, thirds, sixths and sevenths can be major or minor. Providing detailed rules for all interval qualities would be far too complex for this beginners' lesson, and it requires a lesson unto itself. I'll therefore provide a very simple rule that will help you get started.
The difference between major and minor scales lies in scale degrees 3, 6 and 7. (Scale degree 7—the seventh note of the scale—is often raised in minor keys, forming a harmonic minor scale. However, the key signature will still contain the lowered seventh scale degree.)
For example, the key signature for C major has zero sharps or flats:
Its parallel minor, C minor, has three flats:
These flats are the third, sixth and seventh degrees of the scale: E-flat, A-flat and B-flat. (E, A and B are the third, sixth and seventh notes of the C major scale, respectively.) In the C major scale, the interval C to E (the first and third notes of the scale) is a major third, C to A (the first and sixth scale degrees) is a major sixth, and C to B (scale degrees 1 and 7) is a major seventh.
In the C minor scale, the interval C to E-flat (scale degrees 1 and 3) is a minor third, C to A-flat (scale degrees 1 and 6) is a minor sixth, and C to B-flat (scale degrees 1 and 7) is a minor seventh.
This will be plenty of information for the beginning music student. Once you've digested this lesson, it's time to move on to Interval Ear Training.