Petroc Trelawny with music and arts news, including a review of Charles Mackerras conducting Janacek and Mahler at last night's Prom. Music includes Vivaldi's motet Nulla in Mundo Pax Sincera sung by Emma Kirkby with the Academy of Ancient Music after 7.00; and Schubert's Rondo in A performed by violinist Nigel Kennedy and the English Chamber Orchestra after 8.00.