Jazz like dat

It's not often that we get jokes in the mail that (a)we haven't seen at least thrice a year before and (b) make us laugh. Here's one of those rarities. [Thanks Susan.]
Stevie Wonder is playing a gig in Tokyo.
He's just finished playing his seventies classic Sir Duke. The crowd is still going wild when a young man at the front says, "Stevie, you play a jazz chord, you play a jazz chord!"
So the amiable Mr Wonder plays an F# minor on his keyboard and goes off on a jazz riff. Done, he turns to grin at the audience, basking in the applause. As the cheers die down, the young man stands up again. "No Stevie," he says, "You play a jazz chord please!"
So Stevie tries an A and off he goes with the band on this amazing improvised moment. When the blind musical genius finishes, the crowd goes wild once more. But the young man pipes up again: "No Stevie, a jazz chord, a jazz chord!"
By now old Stevie is a little confused. "What do you mean, play a jazz chord? I've just done two for you!"
"But it best song of Stevie Wonder! It velly famous!" comes the reply.
"Ok, well how does it go then?" Stevie asks. The young man clears his throat, closes his eyes, and starts to sing:
"A jazz chord...to say...I ruv you."