On the contrary, I think an apology is probably in order. I hope I'm never too proud to apologize.

You correctly observe, and I have readilly adimited elsewhere, that I have no formal (i.e., university) education in music theory. I have studied theory in an individual lesson setting with a very experienced professional jazz guitarist and it's from that and from forty years of playing with other musicians of many stipes that I derive any (possibly flawed) knowledge I have. (N.B. This does not mean that I actually am a jazz guitarist; I'm definately not.)

Let me explain my own thought process and perhaps you will find the source of the error in my thinking.

I understand, for instance, that there is such a thing as a diminished chord separate and distinct from a diminished 7th chord. In practice however, for the sort of tunes I might play (traditional folk, blues, bluegrass, jazz) the notation “dim” (also °) always refers to a diminished 7th (the four-note chord in which each note is a minor third above the previous one).

A G#° chord (G#dim7) contains the notes G#-B-D-F. For the guitarist, by virtue of inversions, this chord may also be called B°, D° or F° because the intervals are all the same, even when crossing octaves. This would seem to suggest that there are at least four dim7 chords containing the note G#. (N.B. A pedant may prefer referring to G# as Ab to maintain the theory of using evey other note name.)

Similiarly, the notation “7” always refers to the use of the flatted 7th with respect to the root of the chord name (and without respect to any specific key). Often, this is called a dominant 7th chord even though that designation isn't strictly true unless the root of the chord is a major fifth above the tonic of some reference key.

I agree that some confusion arrises from the apparant shift in terminology used when moving the discussion from chords to scales. In a C major scale, the interval from C to Bb is commonly termed a minor 7th meaning that the 7th is flatted. The same Bb note, however, when played with a C major triad (C-E-G) is never referred to as a minor 7th. It's either called a 7th or perhaps a dominant 7th. C-7 (Cm7) would be C-Eb-G-Bb, a minor triad with a flatted 7th added.

You can see that I tend use both the terms flatted and minor to mean lowered in pitch by one semitone when speaking about scales and intervals. I understand that in an academic setting there are specific reasons for using one term or the other but outside of that setting nobody much cares.

I can appreciate what Don is talking about because I know that a formally trained classical guitarist will use the terminology of theory in a most pedantic way. That's appropriate because the classical guitarst is trained to a much wider range of music and situations than many of the rest of us. Not many classical guitarists would prefer to listen to much of the music we discuss here so I'm always grateful for the few who take the time and patience to add their insights.

That said, outside of universities and studios devoted strictly to classical music, I think my rude understanding of theory is what passes for notational communication among the vast majority of professional and amateur musicians. I also use the practice (common among working musicians) of referring to chords by number rather than name. The tonic chord of any key is a I chord, the dominant a V chord, etc. Extensions and ornamentation are often left to the creative descretion of individual musicians and relys on their experience with the genre.

      - Mark

Outside of a dog, a book is man's best friend. Inside, it's too dark to read.

Groucho Marx