This thesis presents critical music edition and analytical overview of eleven movements from a composition “Messa di morti a 4 voci con accompagnamento di piena orchestra”, written by composer Tommaso Resti (ca. 1770 – 1830). According to the data on front page of manuscripts from Franciscan monastery in Dubrovnik, this work originates from 1802. Preserved full score dates probably from 1838. Through the transcription from manuscript to contemporary score and musical analysis of a comprehensive vocal instrumental piece, the first step in the revitalization of an unknown piece from cultural heritage of Dubrovnik will be introduced. The first part of the thesis provides an overview of music history of Dubrovnik at the end of the eighteenth and beginning of the nineteenth century, some music features of the composition and a material description of the original. The second, main part presents features of Tommaso Resti's musical language. All components of the musical work, like melody, rhythm, harmony, form and instrumentation are analyzed. Along with transcription and analysis, the comparison of two original manuscripts was approached in order to show some differences in musical contents and also possible difficulites in transcription. In the end, all changes in piece which the author has made as the part of a critical music edition are noted down. Tommaso Resti lived and composed in the end of the eighteenth and beginning of the nineteenth century and his opus in the Archive in Dubrovnik contains more than fifty compositions. The goal of this thesis is the revalorization of his inheritance and, consequently, the reconstruction of insufficiently researched music history of Dubrovnik.