The composer of The War Requiem and filmmaker Bla Bartk are not from the same country.
Edward Benjamin Britten, Baron Britten {'1': ", '2': ", '3': ", '4': "} (22 November 1913 4 December 1976) was an English composer, conductor and pianist. 
Bla Viktor Jnos Bartk ( ; ] ; 25 March 1881  26 September 1945) was a Hungarian composer, pianist and an ethnomusicologist. 
The War Requiem, Op. 
