Petr Iljitsch Tschaikowsky, whom Igor Stravinsky charakterized as being 'deeply national', represents the culmination of 'Russion Classical music' of the late-eighteenth and nineteenth centuries. Probably the most versatile of Russian composers, he made great and lasting contributions to all genres - operas, ballets, incidental music, symphonies and other orchestral works, chamber music, piano music, sacred and secural choral music, romances, Lieder and folk-song arrangements - establishing a special place for Russion music within the European tradition. Publications of the first complete edition of Tschaikowsky's works was started in the centenary year of his birth, 1940. Publication of a second edition will begin in 1993, the centenary of his death. There are important reason, both editorial and in terms of content, for a second edition to follow so soon. In the old edition, ideological considerations meant that some of the texts which Tschaikowsky set to music were arbitrarily altered. Similarly, quotations of the old Russian national anthem were replaced by other music. A number of works, or independent versions, werde completely overlooked. For example, the full score of the opera 'Vakula the Smith' (the first version of Cerevicki) and the unfinished Symphony in E flat major werde not standardized; in some cases no textual analysis was offered, and critical apparatures were simply dispensed with.The new complete edition will remedy these shortcomings. In addition to the composer's final versions, it will include alternative and earlier versions of works, as well as fragments and incomplete works, all reproduced faithfully from the sources. Documentation and discussion will be provided in Critical Commentaries. Piano reductions exist of the stage works, concertos and concertante pieces as well as of some of the cantatas and orchestral works, either written by Tschaikowsky himself, or revised or authorized by him. These are all to be included in the edition which, with its historico-critical approach, will address the need both of scholars and of practical musicians.The edition of musical works (Serie I-IX) is supplemented by a facsimile edition of all of Tschaikowsky's surviving sketches (Serie X), the texts of his diaries, writings and letters, including the three-volume Tschaikowsky-Mekk correspondence (Serie XI), a two-volume catalogue of works and a single-volume Tschaikowsky Encyclopaedia (Series XII).