But when I eventually pitched up, after 10.30pm, it turned out it was the launch of the One foundation's #agit8 campaign, their fantastic two day event at Tate Modern featuring a host of pop stars playing protest songs, aimed at the leaders due to gather at the G8 in Northern Ireland in a few days.
Quite coincidentally, I happened to have booked today off work and it provided a great opportunity for Lovely Wife and I to take Dear Little Girl to her very first music gig. It was also a bit of an eye-opener for me; while I recognised the names of a few of their artists I didn't know their music. And I wasn't going to hear much either as mainly they were playing the likes of Woodie Guthrie, Radiohead and Bob Dylan.
So Paloma Faith opened the afternoon with a rendition of Bob Marley's Redemption Song:
Jamie Cullum did Radiohead's High and Dry:
Omid Djalili made an excellent joke about dickheads in a Nelson Mandela voice as well as a rendition of 'Iranian Men, Hallelujah, Iranian Men' (just sing it):
And KT Tunstall performed a moving Woodie Guthrie poem which was later set to music:
It was all rather good fun. It was how I imagine music festivals should be; without the people, drunks, drugs, mud and people. I was feeling quite hip for pitching up at these impromptu secret gigs by modern pop stars, quite a departure from my usual choice of music which generally requires the artist to be long dead. This feeling was somewhat punctured when a colleague pointed out only I could describe KT Tunstall and Jamie Cullum were 'radical'. For the record, I don't, but I get the point.
I'd like to tell who else will be performing there later tonight and tomorrow but I can't. You'll just have to pitch up and hope for the best. And it's all in a tremendous cause too, calling on the G8 to do more to tackle poverty around the world. For more info on the campaign go to http://www.one.org/international/
And, I'm pleased to report, Dear Little Girl loved her first live concert experience. I'll try and post a photo later of her grinning.