Sam Inglis wrote:Exalted Wombat wrote:
So the ninth chord built on the dominant would be called "G9", one built on the tonic would be called "Cmaj9". All styles of music agree on that!
That's probably a sensible convention, but in the dim and distant days when I used to hang around with classically trained people, they would use the term 'seventh' to refer to whichever seventh note was diatonic (maybe because they were trained to use figured bass?). So I'm not sure it's quite as universal as all that.
Anyway, it's kind of irrelevant!
Chord symbols, the "C7", "Cmaj9" etc. system of naming chords, are not really a "classical" thing. And yes, "7" in figured bass notation is diatonic (though there are different conventions for whether accidentals against a number are literal or relative).
But when we trained musicians venture into the world of popular music and chord symbols, there's never any question about "C7" including a Bb, whatever key the song may be in. There's no "convention" in pop, jazz or anwhere else where "C7" can be confused with "Cmaj7".