Easily introduce harmonic variety to your songwriting with a roll of the Chord Dice PRO! Six, six-sided dice display all primary or secondary chord extensions. Simply match the number on your Chord Dice to your Chord Dice PRO and play the suggested extended chord. Easily apply all types of sevenths, ninths, elevenths, thirteenths, add 9, and suspended chords. You can even explore minor to major substitutions for a fresh new sound. Chord Dice PRO are to be used in conjunction with an existing set of Chord Dice in any key.