Having suddenly got a taste for live performance after an epic Gershwin concert at the Albert Hall, my dad wonders whether I could accompany him to the Royal Ballet’s Romeo & Juliet. It’s at the O2. “What? the O2, as in rock concerts? the venue formerly known as the Millenium Dome?” The very one. I’m not really a stadium-goer, nor a classical ballet enthusiast, but I know what I like. Pina Bausch, but anyway… Nearly 90, he’s increasingly interested in the arts, but this is a new one on me.

Queueing for my pre-booked tickets in the windswept plaza, I call the wheelchair line, and soon dad is wheeled to meet me by a friendly young attendant. The tickets – a total of £11.25 for a disabled person and carer (yes, I do care) – seem remarkably good value. But our wheeler says she can upgrade us for a better view, and pushes us (him – I’m still walking) onto a balcony nearer the front. On the way she’s ordered me a coffee from another attendant, who brings it to my seat, and charges me: nothing.

It’s vast, the O2 Arena. Really vast. I’m sure there are clouds drifting through it. Whenever I’m in big indoor spaces I imagine myself, somehow, hanging from a little handle in the middle of the ceiling and looking down. Just to terrify myself. Coca-Cola, Sky, Nestlé and the other multi-national carnivores flash their digital messages around the arena till all the lights go down, and spotlights pick out the stage (still a few hundred feet away).

And here’s the problem really: the place is so huge, there are three big video screens above the stage. You know you should watch the stage – this is live performance; but it’s so easy and somehow, strangely natural, to watch the screen. It’s what many of us do all day long, and again in the evening. So I’m forcing myself to watch the stage, but glancing at the screens from time-to-time. It’s the war between two and three dimensions: shape versus space. The screen images are shot straight-on from the front, a viewpoint I like; on the stage is the real thing: life.

Of course, it’s beautifully-danced, and the dramatic Prokofiev is exquisitely played, and the sound is perfect. And, by the end, my hard old eye seems somehow moist. But on the way home, we’re talking about the woman who wheeled him all the way back to the bus stop, the guy who brought me coffee, the cheerful, well, service, of the people who work at the O2.