On the Easel with James Purnell

The back-story to the Seagram murals is a strange tale of rage and despair. The angry young man of Abstract Expressionism is commissioned to produce work for an exclusive dining room at The Four Seasons restaurant in Manhattan, a place billed at the time as 'expensive and opulent... perhaps the most exciting restaurant to open in New York in the last two decades.

Then he changes his mind and, a decade later, the pictures end up in London after long negotiations with many a string attached. They arrive here - with grotesque irony - on the very same morning that the artist is to be found, killed by his own hand on the other side of the Atlantic in a sprawling pool of blood that mimicked the saturated blacks and maroons of the... And so on. Art history becomes art mythology.

So it is that these brooding, mysterious pictures have hung - in their own room - at Tate for nearly 40 years. And I'm just one of the millions who have crept quietly into that room and been overwhelmed by the sheer, dark 'throb' they exude. To be in that room is like being in a chapel, but there is nothing remotely religious about the experience. Heaven alone knows what the New York diners would have made of them, if Rothko hadn't changed his mind. These pictures are not comfortable companions to you as you stare into their blackness, but they never lose their grip. Truly a 20th century work of genius.

James Purnell, Secretary of State for Culture, Media and Sport