In 1973, Britten was too ill to attend the premiere of Owen Wingrave and the Covent Garden performances of Death in Venice. As he wrote sadly to Leonard Bernstein, “they must look after themselves”. Few people in the music world didn’t know the American conductor and composer. In Nigel Simeone’s editorial labour of love The Leonard Bernstein Letters (Yale, T £23) some of the most entertaining letters come from Bernstein’s correspondents. A 27-year-old Stephen Sondheim gives detailed feedback on performances of West Side Story (“Sometimes the hand for America hardly covers the scene change”); Louis Armstrong addresses “Daddy Bernstein” – “Man I sitting in your office rehearsing my lines, and it is knocking me out”; a 10-year-old Yo-Yo Ma offers to play for him; an unknown John Adams chides him for “turning his back” on “new” musical trends; and Jackie Kennedy thanks him for arranging the music for Bobby Kennedy’s funeral mass.