BARTÓK Béla (1881-1945) and others. Set of notes and corrections by Béla BARTOK, Alexandre GRETCHANINOV and William WALTON. Corrections for first auditions by the Boston Symphony Orchestra. BARTÓK Béla. 2 reprographed lists of corrections made by him for the first audition of the Concerto for Orchestra on December 1, 1944 (conducted by Serge Koussevitzky); on the first list (1 large page in-fol.), each of the numerous corrections has been crossed out in red pencil (after transfer to the score), two have been cancelled in ink; the 2nd page (oblong in-8) reproduces 7 and 5 bars to be changed in the trombone part of the 5th movement. GRETCHANINOV Alexander. Autograph musical manuscript (1 page in-4) giving 13 bars to be changed for the first performance of his Missa Œcumenica op.142 (February 25, 1944, conducted by Serge Koussevitzky), i.e. 3 passages for the "Alto-Solo" part of Credo 2 for the "Basso-Solo" part of the Agnus Dei; list of numerous corrections (3 pages and a half in-8), in Russian, in pencil and ink, with 7 musical quotations . WALTON William. Page in-4 of corrections for the first performance of his Cello Concerto (January 25, 1957, conducted by Charles Munch), relating to the 3rd movement, with L.A.S. of November 27, 1956 (1 page in-8, envelope to the librarian of the Boston Symphony Orchestra), indicating that he addressed to Ch. Munch the pages 29-30 of the 3rd movement redone