You know when a song keeps popping into your mind? Like when you're in the supermarket thinking, ooh, I need to get some leg razors, and Welcome To The Jungle! blasts in your head?
That's how you know it's a catchy song. What's the catchiest song right now? Bob and Bono's baby, Do They Know It's Christmas Time?
Thirty years on from the original 1984 record, Geldof returns to marshal indecisive musical temperaments into action.
This time it's Ebola he's fighting. The stars look younger. There are fewer shoulder pads and acid rinsed jeans. There's also more passion; stars like Rita Ora blow their anaesthetised 80s cousins out of the water.
It's also copping serious flak from the public. You'd think the song suggested skinning chinchillas and putting them on fairy bread.
The bulk of the criticism is that this is sung by a score of smug squillionaires. Apparently these guys are avoiding taxes, travelling in by separate private jet and may not actually be donating to Ebola. Yet they're telling the public to cough up? They could probably solve the problem in a whip-around.
People are grumbling that the real heroes, like Medicins Sans Frontiers or the Disaster Emergency Committee, are being ignored. Celebs just ponce in for a few hours, sing a ditty, soak up praise and swan off.
And people feel the lyrics are condescending.
I could write a whole other article on whether or not the lyrics were condescending.
But for space reasons, I'm only going to address the first problem.
So are celebs just giving up a few hours to do some hypocritical, ineffective PR that we're better off without?
No. Geldof and Co aren't just giving up a Saturday morning lie in and Suduko. They're not just toddling down, belting out a line and waltzing off for a latte.
These guys are some stunning singers. They've got incredible talent. This is what they live for. This is how they survive. And this is what they're giving to the cause.
What else were they going to do? They're not trained for anything except music. They can't exactly descend in a cloud of glitter on to Guinea, antiviral drugs at the ready.
I wouldn't trust most of them to use a teaspoon correctly, let alone a scalpel.
That's why we have Medicins Sans Frontiers. Their job is to fight it on the frontline. And they really are more heroic than the celebs.
Band Aid's job is to make music that shakes you. Music that reaches into your body and grabs your heart strings and twists them until you can't breathe. They need to evoke a feeling of deep, struggling urgency in every listener. A call to action.
That restless feeling is where change comes from. At Live 8 in 2005, musician Noel Gallagher mocked the movement to drop African debt.
No politician, he sneered, would listen to Live 8 and think, "Oh, they've got a point. Let's drop the debt." But that's exactly what can happen.
Movements start when someone thinks, "This isn't good enough. I'm going to change this." And that epiphany comes from a deep, painful emotional reaction.
This reaction is what's going to inspire aid workers to keep going. It's what's going to make doctors work longer and harder to find a cure. It's what's going to make politicians remember their humanity and pledge support. That's also how you get long-term change.
Yeah, Bono et al should donate to Ebola. And if they all donated a few cars and the odd crystal Elephant, they could probably raise $50 million. It might even stop this outbreak of Ebola. But Bono et al also need to keep making this sort of music, because it sparks long-term change. Tackling a pandemic or poverty requires long-term strategies. They need the sort of numbing detail that the Government or multi national companies excel in.
How do you move these seemingly faceless corporations?
You remind an MP why they're an MP. You remind a scientist why they became a scientist. You remind them why they're human.
You make them so full of emotion that they pace the kitchen at night, eating sugary cereal from the box. When they're full to the brim of emotion, they act.
They sway other people, they sway parties, and they sway a Government.
What's a great way to fill someone with emotion? Music.
As long as Band Aid is creating an emotional response, as long as it is inspiring future leaders and do-ers, then it's doing the right thing. And it's a big job to do.