His influence can be seen principally in the symphonies and chamber works. These eighteen months were probably the most formative in the composer's life. A less favourable reception was given to his last opera New Year.
His deeply held humanitarian and pacifist beliefs shaped both his life and his music: he served a prison sentence as a conscientious objector in the Second World War. The libretti of his operas which he wrote himself attracted criticism for their allusion-heavy complexity and sometimes awkward and not quite idiomatic use of contemporary slang but have also received praise from amongst others noted music critic Andrew Porter the director Peter Hall and conductor Colin Davis. Sir Michael Kemp Tippett OM CH CBE (2 January 1905 – 8 January 1998) was an English composer.