Viola-Trilingual preface (Ital/Eng/Ger) Detailed critical commentary (Eng)Straight-forward well-presented Piano reduction (Lat)In this new scholarly-critical edition of the Messa da Requiem the editor on the basis of all available sources succeeds in presenting practical suggestions to solve musical problems and those concerning the interpretation of this famous work. A hitherto unexamined handwritten reduction for Voice and Piano casts a new light on the evaluation of several known sources and leads to new philological and editorial decisions.This edition presents a detailed critical commentary as well as a preface on the genesis andhistory of the work. In addition the preface includes a short section on the most important editions published in the 19th century and compares them with regard to problematic passages in the work and the suggestions they made to solve musical problems.