I guess by now everybody knows that yesterday we lost Chuck Berry. Anybody with an interest in popular music knows what an important figure he was, so there's no point in running over that again (John Lennon said that it all started with Chuck Berry, and he wasn't far wrong). But like any other form of evolution, there's no clear cut moment when jazz, blues and gospel became rock and roll. Just as there's no set moment in time when you can point to dinosaurs becoming birds - rather a whole slew of intermediary fossils charting the progression over millennia - so it is with music. Chuck Berry - and Little Richard, and Elvis Presley, and Jerry Lee Lewis despite his different instrument - were all influenced by a formidable lady named Sister Rosetta Tharpe, and now seems as good a time as any to share a little music. So there's a couple of songs beneath the cut. If this doesn't make you smile today, it's a fair bet nothing will!