Musicology Annotation << Back N.A. Rimsky-Korsakov’s participation in ensembles to «Mitrofanov day» Elena V. Stepanova In article the chamber and tool ensembles devoted to the famous patron and the publisher M.P. Belyaev are considered. Works were written by N.A. Rimsky-Korsakov in the commonwealth with other composers – participants of «Belyaevsky Fridays». The appeal to collective compositions «on a case» demanded the solution of certain tasks: correlation of own musical material with the material written by other authors, compliances of work of the identity of the addressee, dedication to a certain event – «To Mitrofanov to day». Ensembles became result, each of which submits the individual creative solution of these tasks. Compositions differ in a musical and fi gurative system, composition, genre and thematic features. Works to «Mitrofanov to day» were not only part of the tradition of the collective composition presented in the XIX century, but also a tribute to the organizer of known musical meetings «Belyaevsky Fridays». Keywords: Rimsky-Korsakov, chamber-instrumental ensembles, collective works, Belyaev, work «on the case», Russian music. Contacts: E-mail: no_vikova@list.ru Pp. 33-40.