Leonard Bernstein is not only a deeply passionate musician, who communicates

Leonard Bernstein is not only a deeply passionate musician, who communicates this commitment to audiences — he is also a man of deep political convictions, who has never hesitated to nail his colors to the mast in support of causes which he believes in.
Thus he agreed immediately to a suggestion by Justus Frantz to conduct Beethoven's Ninth Symphony at Christmas time on both sides of the Berlin Wall. Tt was decided at the outset that, in addition to the Bavarian Radio Symphony Orchestra (of which Frant/ is Artistic Adviser), the players should include orchestral musicians from the countries allied against Germany in the Second World War. The nationalities of the singers would also reflect the symbolic nature of these two concerts: the former victors and the former defeated from East and West — united in music, that art form which has always contributed most to promoting understanding between peoples.
Bernstein's primary intention was, as he has said himself, to observe a "celebration of human freedom".
Hanno Rinke Deutsche Grammophon