--although music theory debates are fun..--may I be so bold as to quote the late great Bill Evans.
Jazz is not an intellectual process, we use are intellect to understand it, but it takes years and years of practice to forget all that and just play.
This quote rings true on so many different levels! An intellectual understand (of seventh chords for example) must be established in order to lead to effortless improv (with seventh chords etc...). And...I think intellectual understand includes
aural recognition and mastery of musical objects as well! Simply being able to regurgitate the interval content of a given seventh chord is worthless in the heat of improv if our ears aren't engaged...
Personally, I like to categories seventh chords using a "double m" system. The first m gives the triadic content and the second m, the seventh note content.
M stands for Major and
m for minor yielding...
MM7 (used extensively in Impressionistic music and Jazz ballads)
Mm7 (otherwise called the dominant 7th chord...the most frequently occuring 7th chord)
mm7 (normally of predominant function, i.e. as a ii7...great for dorian scale riffs etc.)
mM7 (awesome color chord used in myriad ways at the end of minor mode jazz pieces! I think various arrangements of the James Bond theme end with this chord...9th is normally added for more color!)
*note...this leaves out 7th chord possibilities with diminished and augmented triads! Some awesome sounds!
It's also cool to experiment with substituting the normal or diatonic 7th chord on a given scale degree with another type.
For example, we normally use a Mm7 i.e. dominant seventh on the 5th scale degree...e.g. - a G dominant 7 in the key of C major. Well...if we change that G dominant 7 to a GMM7 or a Gmm7, all of a sudden, our chord progression can end up in some pretty awesome, far-a-field places! Then...enjoy the harmonic journey of getting back to the home key!
Joseph Noelliste
Solo Pianist and Composer
www.jnoelliste.comwww.facebook.com/jnoelliste