Derek and Dave Philpott have been writing strange letters to famous musicians for ten years now, and getting even stranger ones back. Their first book, Dear Mr. Kershaw, became a cult hit and the follow-up Dear Mr. Pop Star was released by Unbound Publishing to more acclaim. And now they return with a Punk edition, Grammar Free in the UK, which is raising money for the charity Crisis. Dave tells us how these extraordinary projects came about, and how it first gained momentum when his dad saw how many Facebook friends he had and suggested, 'Why not ask them for a tenner each?'