The_Complete_Idiot%27s_Guide_To_Music_Theory

If you’re working with extended chords, there are more than two possible inversions.
For example, the third inversion of a seventh chord puts the seventh in
the bass; the fourth inversion of a ninth chord puts the ninth in the bass.
The particular order of a chord’s notes is also referred to as that chord’s voicing.
You can specify a voicing without writing all the notes by adding a bass note to
the standard chord notation. You do this by adding a slash after the chord notation,
and then the name of the note that should be played on the bottom of the
chord.
For example, if you want to indicate a first inversion of a C Major chord (normally
C E G, but E G C in the first inversion), you’d write this: C/E. This tells
the musician to play a C Major chord, but to put an E in the bass—which just
happens to be the first inversion of the chord. If you wanted to indicate a second
inversion (G C E), you’d write this: C/G. This tells the musician to play a
C Major chord with a G in the bass.
You can use this notation to indicate other, nonchord notes to be played in the
bass part. For example, Am7/D tells the musician to play an A minor seventh
chord, but to add a D in the bass—a note that doesn’t exist within the A minor
seventh chord proper.
An A minor seventh chord with a D in the bass—not your standard seventh chord.
Adding Chords to Your Music
When you want to indicate a chord in your written music, you add the chord
symbol above the staff, like this:
Write the chord symbol above the staff.
The chord applies in the music until you insert another chord. Then the new
chord applies—until the next chord change. For example, in the following piece
of music you’d play a C Major chord in measure 1, an F Major chord in measure
2, a C Major chord in the first half of measure 3, a G7 chord in the second
half of measure 3, and a C Major chord in measure 4.
Chapter 9: Chords
123
Warning
Don’t confuse the
chord/bass notation with
chord
the similar (like a
chord
fraction with a horizontal
divider, as opposed to
the chord/bass diagonal
chord
slash). The notation
chord
tells a musician—typically
a pianist—to play one
chord over another. For
Cm
example, if you see ,
Dm
you should play a Cm
chord with your right hand,
and a Dm chord with your
left.