Ebony and Ivory is a Terrible Metaphor for Race Relations

This is from my first novel 'The Cybermancer Presents'. Two characters are walking past Speakers' Corner in Hyde Park, within a Grand Theft Auto-type videogame set in 1980s London:

'And that's why Britain doesn't care for the black man!' he concluded.

'But hold on,' said a voice from the audience. 'How can you say that? 'Ebony and Ivory' was number one for seven weeks! They still play it on the radio. And that was all about racial harmony. It was even banned in South Africa because of its message of inclusion. How can you say Britain doesn't care about race relations?'

'Ebony and Ivory? Say what?' He was getting into his stride now. 'Have you ever seen a piano keyboard? I mean, have you ever really looked at it? What do we know about the black keys? They're in the minority and they're standing at the back. They have no opportunities compared to the whites. You know what you get if you're a black key? A pentatonic scale. Five notes. That's it. None of the fancy-arsed semitone intervals the white notes get. Oh no. You know how many chords the black notes can make? Two. An F sharp and an E flat minor. Two chords. That's it. They're not even in the same key! We don't even have keys. You need seven notes for that and we only have five. You know what you get if you're white? A whole octave. That's right, a whole octave that you and your white buddies can play around in to your heart's content. That's enough for three major chords, three minors, and a diminished. You know what diminished means to a black man? A reduced responsibility defence in a murder trial because the CIA have filled him with crack! White notes have a whole octave of things they can do. Black notes can do almost nothing. And you know why? Because 'Ebony and Ivory' was written by a white man. Because the piano was invented by a white man. Why do kids learn in the key of C? It's not because it's easy. It's because it's white!'

'But what about accidentals?' said the man in the crowd. 'You seem to know a bit about music. You can't play something in the key of E flat or whatever until you use both black and white.'

'There are seven notes in a key,' said the speaker again. 'There can never be equality. At best it's four of one and three of the other, with the three oppressed by the four and resenting them. The white notes sound good on their own, the black notes sound good on their own, but if you mix them up and you don't know what you're doing, you get discord.' He ended with another rhetorical flourish. 'And that's what we've got in Britain today, folks – discord!' He bowed to a smattering of applause. This guy was more interesting than the usual Christian nutters who turned up. He was a showman. And the name of the game was entertainment. That was what politics was all about. Even the US president was an actor.

Ram and Raffles looked at each other and walked on. Interesting guy. Ram privately agreed with the speaker. He thought that a zebra crossing would have been a better metaphor. It doesn't matter if you're black or white. You still get alternately stepped on or run over your whole life and you get no opportunity to do anything about it.