The visit by the Pittsburgh Symphony Orchestra conducted by Lorin Maazel is one of the highlights of this year's Henry Wood Promenade Concerts and echoes the American theme. Founded in 1926 the orchestra's past conductors have included Fritz Reiner , William Steinberg and Andre Previn. Tonight's programme, recorded earlier this evening and introduced by Jane Glover , will include an interview with Maazel who was himself brought up in Pittsburgh. It consists of one work only: the Symphonie fantastique by Hector Berlioz. Berlioz wrote of its first performance in 1830: 'I had a wild success! It was received with shouts and acclamations: they had to repeat the March to the Scaffold; and the Witches' Sabbath was quite overwhelming in its satanic effect.'