According to
The New Penguin Dictionary of Music, Mikhail Mikhailovich Ippolitov-Ivanov was a Russian composer, pupil of
Nikolay Andreyevich Rimsky-Korsakov; director of the Moscow Conservatory. Studied folk-music, e.g. of Georgia, and wrote orchestral "Caucasian Sketches" and other regionally entitles works - also 2 symphonies, operas, many songs, etc. Completed Mussorgsky's unfinished opera "The Marriage".