Paul Vallely: Cheap music brings out the best in us

Emotion plays a bigger part in public life than we often suppose. When the mass killer Anders Behring Breivik announced he detested a song he claimed had been used to brainwash the youth of Norway into supporting immigration, some 40,000 citizens gathered in the centre of Oslo to sing it in defiance. When a 30-year-old runner in the London marathon collapsed and died near the finishing line a shocked British public went onto the website where she had hoped to raise £500 for the Samaritans and made donations that now exceed £1m.

But the donors who went on to Claire Squires's JustGiving page also wrote some odd things. She was brave, they said, and "an angel" who had sacrificed her life for others. It is not to diminish the sadness of the Leicestershire hairdresser's death to say that such comments make no rational sense. It was not as though the poor woman had known that she might die and had decided to run anyway. But hyperbole is part of the language of bereavement, public as well as private. Strangers felt touched, at an unexpected depth, by the intimation that their own death could be as arbitrary – or as imminent. Their small donations assuaged the little grief that their moment of empathy had pricked.

"Extraordinary how potent cheap music is," says Amanda in Noel Coward's Private Lives. The song to which the killer Breivik objected had a jaunty little folk tune and the hit version in Norway was played on a preposterous ukulele. But the two women who announced on Facebook that they were going to sing it, expecting a couple of dozen friends might join them, found that almost 1 per cent of the entire Norwegian population turned out. They sang in the rain, waving red and white roses, the colour of blood and bandages: "Together shall we live, every sister, brother, you and me, young children of the rainbow." But they were not singing for someone else. "We aren't here because of him, but because of each other," as one person.

Breivik got to hear of it. He pronounced the collective singing "illogical". We have seen where his logic leads. On the website where the video of the mighty crowd's gentle song was posted, nasty internet trolls added poisonous ultra-nationalist rhetoric in response. That showed how necessary it was for Norway's silent majority to break its silence. A song was a more effective response than any statement could have been.

Sentimentality is desiring the luxury of an emotion without paying for it, Oscar Wilde once said. Some say that there is a falseness about sentimentality, but it is more a superficiality, a transience or lack of proportion: Hitler wept watching a pair of lobsters boiled, yet unblinkingly sent millions of people to their deaths. Emotion becomes sentiment when we look at others and then project their plight onto ourselves. It is why cheap tear-jerking movies work; it descends into the self-indulgent, the maudlin or the mawkish. It is selective. It dilutes intense feelings to a safe strength.

But there are thoughts that lie too deep for tears. With sentiment, little really alters; but emotion prompts change, so that something – however small – is never the same again. The donations to Claire Squires's web page are an intuitive ritual acknowledgement of that fact. But the stand taken by the Norwegians went beyond the ritual into the political.

Feelings are a necessary precondition of rational thought and action, for without emotion to prick our moral sense, as the philosopher David Hume argued, reason would remain dormant. But it has to be emotion which empowers and not a narcissistic sentimentality which indulges. And that requires self-awareness. Coward knew that: the cheap music Amanda overhears is a hit from years before – written by Coward himself.