Chord Names

What are the general conventions for triad chord names?

Triad chord names are constructed from a note name plus a mode, Major or minor.  For example, C Major.  C is the root, or tonic, and the term Major tells you how to select the three notes are separated by intervals of 4 and 3.   Thus C Major is C-E-G.  As a shorthand, the term Major is sometimes omitted, so if there is no mode specified then assume it's Major.  So C Major may be just called C for short.  On the other hand, if the mode is minor it must always be specified, e.g., C minor.

Why the same chord name can mean things different 

The triads F-A-C, A-C-F, and C-F-A may all be called F Major.  So how do you know which is which.  From just the name F Major, you don't.  If there's no further explanation, then it's a matter of context.  In most cases when a chord is being defined (say, in a reference book or a table of chords), the chord name and the tonic are the same.  Thus F Major is F-A-C by that definition.  But then in playing instruction materials (even in this site's course), it may be different from that (e.g., C-F-A).  Welcome to the world of music terminology.

You create different forms of a chord by re-ordering the notes.  Re-ordering the notes is done by raising the lowest note by an octave.  In the music world, this is called inversion* even though it's really more of a shuffle.  Thus to get from F-A-C to C-F-A, you have to shuffle twice.  First, deal off the bottom of the deck by moving scale-wise the F from the bottom to the top.  This raises it an octave to produce A-C-F which is called the first inversion of F Major.  Then shuffle another time (move A to the top) to get C-F-A, the 2nd inversion.  You may or may not see the qualifiers 1st inversion or 2nd inversion added to the chord name so watch out.   What further makes this situation confusing is that the inversions no longer have the 4 and 3 interval counts between them and so no longer follow the convention for Majors.

Chord names containing the number 7

What does the number 7 mean?  Going back to the lesson "Intervals and chords", you may remember how interval names are based on the ordinal number of the original 7 note scale.  Likewise, the "7" in a chord name relates then to the 7th note in the old scale.  But there are two interval names like this: a Major 7th and a minor 7th.  So which is it?  Well, it turns out to be the minor 7th with an interval count of 10 unless it explicitly is further annotated as Major.  So minor in this context is the "default" mode for the number 7 in a chord name (whereas a missing mode from a chord name defaults to Major!).  

OK.  Back to the chord name.  When you see a chord name G7, it means the triad G Major, which is shortened to just G as described above, with a minor 7th added.  Thus, the triad G-B-D is converted to a four note chord G-B-D-F.  Were this always the case.  Read on.

same names, different chords

Often in lessons for beginners a four note chord may be simplified to have only three, a triad.  Alas, the lessons may still refer to the triad with the same chord name as the original four note chord.   The G7 chord B-F-G (as seen in the lesson "The G7 chord triad") is an example of a simplified chord.   Let's analyze how a full 4 note G7 chord G-B-D-F becomes the simplified B-F-G.  First, invert the G7 chord to make it B-D-F-G.  Next drop the D note to get the B-F-G triad.  So the two chords are different but they sound similar.  And of course for beginners the triad is a lot easier to play.  In this course, the term triad will always be attached to the chord name for clarity.


OK maybe after reading all of this you may think that memorization approach is not looking so bad now.  Don't expect all of the above to sink in, not in just one reading anyway.  So just memorizing chords as you learn them is sufficient to play them and continue in this course.  But perhaps in the future as you encounter a chord and think "What the ...", you may return here to help sort it out.  Not that this is page covers everything.

*The word inversion means a reversal, so this would suggest the inversion of F-A-C  by the dictionary definition would be C-A-F, but not in the world of music.