The chord chart below features chords which have one or more alterations to one of the given formulas, and are therefore called altered chords, as described in lesson 46.
In altered chords, the notes to be altered are always written as part of the chord name, enabling you to construct the chord. For example, a Cm7#5b9 (not listed above) is a Cm7 chord with the fifth sharpened (#5) and the ninth flattened (b9). When you are working out a suitable shape for this chord, remember that the root note and/or the fifth note may be omitted.
Another type of alteration occurs when chord symbols are written thus:
Example 1: G/F# bass
This indicates that a G chord is played, but using an F# note in the bass.
Example 2: C/G bass
This indicates a C chord with a G bass note.
Sometimes the word "bass" will not be written (i.e. the symbol will be just G/F#), but the same meaning is implied. These chords are often referred to as slash chords.