Plot: BBC2 joins Radio 3 in stereo for a live relay of the first half of this evening's Prom from the Royal Albert Hall. Mozart Symphony No 39, in E flat (K 543) Shostakovich Violin Concerto No 1 Ida Haendel (violin) Royal Philharmonic Orchestra guest leader BARRY GRIFFITHS conducted by Hans Vonk Introduced by PETER BARKER Sound GRAHAM HAINES