Click http://www.mikesmusicroom.co.uk/chordbook.html to learn how to play 7th chords and download the complete keyboard chord book which includes 12 major chords, 12 minor chords, 12 seventh chords and 12 minor seventh chords.
The three 7th chords in this video are:
A7 Major Chord
E7 Major Chord
B7 Major Chord
Keyboards Sale – Auction Page:
http://musical-instruments-uk.mikesmusicroom.co.uk/Keyboard-Piano/Electronic-Keyboards