-The rule of 9 - Figured Bass - 6/6-4

For diatonically-named intervals, there is a useful rule applying to all intervals (that is those of one octave or less). The number of any interval and the number of its inversion always add up to nine. Thus a fifth (number 5) and its inverse or complement, a fourth (number is 4) add up to 9. Do not forget that chord quality is still a factor. Majors are inverted to minors and vis versa. Perfects are preserved when inverting, but this is the only exception. A major 6 th becomes a minor 3 rd

In figured bass, Arabic Numbers (figures) are written below each bass note. These figures refer to intervals above the bass (usually assuming octave equivalence). In a root-position triad, the intervals above the root are a 5th and a 3rd, giving the figures 5/3. Normally, however, this is abbreviated by assuming that any bass note given without symbols indicates a 5/3 chord by default. Similarly, the full figuring of the first inversion ( 6/3 ) is abbreviated to just ; the full figuring of the second inversion ( 6/4 ) has no abbreviation. “I use figured bass in all my music”

When a chord is denoted as a “6” chord, the top note of the chord is placed at the bottom of the triad. For instance, in a C chord, we have CEG. In a C6, the G is place on the bottom thus resulting in GEC being what you play. The top note becomes the root without the quality of the chord changing. “Using inverted chords in my songs makes the crowd really go wild.”

In a 6/4 chord, the middle note of the original triad is played as the root while the top note is played as the middle note. In a C chord, we have CEG. When we have a C6/4, we have EGC. The quality of the chord never changes. You play the same notes, just at different pitches. “I love what I do”