Prince wrote some of the greatest chord progressions in all pop music. He had all sorts of tricks up his sleeve. But he really loved to use 9 and add9 chords. They’re peppered all over his songs and it’s well worth adding them to your own bag of tricks.
Prince’s most iconic use of the chord is the E9 in Kiss:
Can't think of a better tribute than strumming 7677 nine times. pic.twitter.com/HQFPCURfGq
— UkeHunt (@UkeHunt) April 21, 2016
He often used it where you might expect a 7 chord e.g. at the end of a chord progression to create tension and propel the progression back to the beginning. But while 7 chords are strident, 9 chords are more diffident and melancholy.
For example, he used F9 at the chord progression in the verses of How Come You Don’t Call Me Anymore?:
And a D9 the end of the little cadence leading into The Most Beautiful Girl in the World:
But the best use of them ever has to be in Purple Rain. In that song he used 9 chords at the start and end of the progression:
As always with chord progressions, if you hear something you like feel free to steal it and make it your own. You wouldn’t be the first to do it with this tune. Take the F chord out and you have Mayonaise by Smashing Pumpkins: