There are many types of chords that come from the ‘dominant seventh chord’-family.
All these chords can be used in swing- and jump-blues.
These chords all have in common that they use the formula 1-3-5-b7.
By ading notes to this formula, we color the chord.
The most commonly used colors in swing- and jump-blues are 9th and 13th.
A ninth chord has the formula : 1-3-5-b7-9
The 9th can be found one whole note (2 frets) above the root.