Task: Question Answering
Input (English): Passage: In 1958 Poulenc embarked on a collaboration with his old friend Cocteau, in an operatic version of the latter's 1930 monodrama La Voix humaine. The work was produced in February 1959 at the Opéra-Comique, under Cocteau's direction, with Duval as the tragic deserted woman speaking to her former lover by telephone. In May Poulenc's 60th birthday was marked, a few months late, by his last concert with Bernac before the latter's retirement from public performance.Poulenc visited the US in 1960 and 1961. Among his works given during these trips were the American premiere of La Voix humaine at Carnegie Hall in New York, with Duval, and the world premiere of his Gloria, a large-scale work for soprano, four-part mixed chorus and orchestra, conducted in Boston by Charles Munch. In 1961 Poulenc published a book about Chabrier, a 187-page study of which a reviewer wrote in the 1980s, "he writes with love and insight of a composer whose views he shared on matters like the primacy of melody and the essential seriousness of humour." The works of Poulenc's last twelve months included Sept répons des ténèbres for voices and orchestra, the Clarinet Sonata and the Oboe Sonata.On 30 January 1963, at his flat opposite the Jardin du Luxembourg, Poulenc suffered a fatal heart attack. His funeral was at the nearby church of Saint-Sulpice. In compliance with his wishes, none of his music was performed; Marcel Dupré played works by Bach on the grand organ of the church. Poulenc was buried at Père Lachaise Cemetery, alongside his family. 
Question: What is the last name of the person whose last concert with Bernac before his retirement from public performance marked his birthday late?
Output (English): Poulenc.