Here's an example of one I spotted a couple of days ago, from a charity:
There's a great night of classical music ahead for Amy's Sarcoma Symphony Orchestra @funkeyryhmes http://t.co/IpLltleHQo
— Sarcoma UK (@Sarcoma_UK) December 27, 2013
Each charity will promote their event to their supporters (and not just via Twitter of course!) and musicians and special guests will do likewise to their fans etc.
It occurred to me that people who aren't connected with either the charity, or the people performing at it, might still like to know about these events - and if they would, where would they look?
Is there a charity concerts listing, that visitors can update themselves ("submit your event")* - and is there even much of a need for one? There might not be.
If I want to go to see a film I can check the local listings and see where it's on. But I can also look at the overarching listings and see that a much-loved film will be showing at some location I'd never heard of - the existence of the overarching listings means that I'll hear about other stuff. That's what I imagine the benefit of a charity concert listings might be, to augment the signal a bit.
I suppose I tend to see more than one example of 'something in a particular category' (in this case charity music events' as an indication that the category itself might be curated!
Here's one I've found: "Charity Concert" | Events | The List - it looks interesting but I don't think I can auto-submit an event.
*presumably the time cost of this is that for the website to work efficiently there'd have to be someone who'd receive a notification that a new event needs approving and then approve it. Without that it will end up being filled with spam.