Ever the cynic, I am usually suspicious of celebrities privatising grief.

Of course they will want to sing at the Manchester concert organised by Ariana Grande, who no one over 30 had ever heard of before last week.

The cynic says, it brings good PR. Exposure to new markets. Downloads through the roof...

But as I watched the concert with my children on Sunday night, I realised that if there is any point to our vacuous celebrity culture, then this must be it.

For who but musicians can bring so many people together and get them feeling and thinking in such powerful, positive ways?

No politician could touch today's audiences quite like the unexpectedly well behaved Liam Gallagher with his extraordinary 'Live Forever' tribute to 'the beautiful people' who died in the horrific attack on the Manchester Arena; all the more special because he sang it with Coldplay's Chris Martin, the edgeless musician he would certainly have sneered at once upon a time.

The absence of Liam's brother Noel was of course a disappointment.

Fans were hoping for a longed-for reunion of their band, Oasis, after it so spectacularly fell apart in 2009 when their endless fraternal feuding finally got too much.

Who better than Noel and Liam to show their home town of Manchester that love conquers all by ending their animosity in such a public way?

But Noel – the brilliant, empathic lyricist whose songs were the heartbeat of the evening, albeit in his absence - will have no doubt felt it wasn't the right thing to make the event about the two of them.

Some of those who didn't come looked like they might have made more of an effort.

David Beckham – what really was more pressing for you these days?

But in Noel's case, staying away seemed like a brave decision to risk public wrath, and leave it to his so-often errant younger brother to get it right for once, which he finally did, beautifully and spectacularly.

By being absent, Noel reminded everyone that what mattered most of all on Sunday night were not the people who were there, nor the people who couldn't be bothered to be there, but the people who would have loved to have been there, but no longer could.