I am learning Music Theory from several different sources and I am currently concentrating on intervals and moving into building chords using intervals.
I am trying to find patterns in order to reduce the amount of raw data that I need to learn.
I have noticed that...
...a Major 7th chord, uses a Major Triad (1-3-5) and adds a Major 7th interval (1-3-5-7)
...a Minor 7th chord, uses a Minor Triad (1-b3-5) and adds a Minor 7th interval (1-b3-5-b7)
This appears to suggest a patten of (Base Chord) + 7th interval also based on the name of the chord.
ie Major Triad + Major 7th = Major 7th or Minor Triad + Minor 7th = Minor 7th
UPDATE: The following text was found to be based on incorrect data found on the internet (Who'd have thought :P)
This does not appear to ring true with 6th chords.
...a Major 6th chord, uses a Major Triad (1-3-5) and adds a Minor 6th interval (1-3-5-b6)
...a Minor 6th chord, uses a Minor Triad (1-b3-5) and adds a Major 6th interval (1-b3-5-6)
ie Major Triad + Minor 6th = Major 6th or Minor Triad + Major 6th = Minor 6th
The interval added to form a 6th chord appears to be the inverse of the name of the chord. So a minor interval is added when the chord is major, and a major interval is added to a minor chord.
Is there a reason for this apparent inconsistency?
Is there some sort of rule which I can use to predict higher order chords? (9ths 11ths etc)