Plot: On Friday Omnibus visits the Royal Albert Hall , London, for the first of six programmes featuring highlights from the 91st season of Henry Wood Promenade Concerts. Tonight Jane Glover sets the scene for a series about one of the most popular music festivals of the year and offers glimpses of rehearsal, performance and comment from among the many celebrated musicians who will be appearing including Salvatore Accardo, Peter Donohoe, Lorin Maazel, Jessye Norman and Simon Rattle