This project representing the basic source research, aims to explore the remains of a not anymore extant musical collection of moravian bishops Leopold Egk and Maximilian Hamilton from years 1759-1763. An important amount of music works from this collection extant in the musical archive of benedictines in Lambach will be selected, compared with extant thematic catalogue from 1759, cathalogized and published by critical-practical edition and presented in concert form.