Dame Judi Dench on why laughing makes it easier to play tragedy and novelist Susan Hill on taking a break from crime fiction. In Derry-Londonderry (UK City of Culture 2013) award-winning novelist Jennifer Johnston reflects on fictionalising the Troubles...and the Turner Prize for Modern Art – leaving England for the first time. Kirsty Lang meets the band Earth Wind and Fire and John Wilson talks to film-maker Clio Barnard.