Busking

I think nearly every teacher’s favourite part of the job is running extra curricular clubs or workshops. I’ve always wanted to have more time to do these things, but with the pressure of preparation for exams it’s always tough to justify spending a good amount of time on planning and running them.
One thing that the students have run themselves (normally for a fundraising day) is a lunchtime of ‘Busking’ around the school. A bunch of them brought guitars, played a variety of contemporary hits and classics they knew and the school had a really awesome atmosphere.
One thing the kids couldn’t really do well was re-configure a song well for busking or pick something more left-field (there was a lot of Mumford and Sons and Oasis).
I have a few lunchtimes free this term and I’m thinking of having a few open-mic/workshops.
And so I ask, What songs would you most want to see performed creatively by a busker?