240 Seventh Chords Piano Pages   William Wieland
Prerequisite: Dominant Seventh Chords
5 Seventh Chords x 4 Inversions x 12 Keys = 240
For example, begin with dominant seventh chords. Play a G7 chord in its 4 Inversions. Next play a C7 in its 4 inversions. Continue through the Circle of 5ths. When you have played all 12 dominant seventh chords, choose another of the 5 Seventh Chords and repeat the process. Continue until you have played 240 chords. Practice until you can play all of the chords without a mistake.
This exercise is from Dr. Mike Pagan, UMKC Conservatory of Music jazz pianist and composer.