Kozyol-muzykant

The short is a satire of composers who merely compile existing tunes in favor of actual creativity. As a musician, the goat, on the advice of his donkey friend, composes a symphonic work based off of Zhil-byl u babushki seren'kiy kozlik ("Once grandmother had a gray goat"). The goat's concert is preceded by the gray wolf, considered to be a respected musicologist. While he appreciated the composition, the audience took to leaving their seats dismissing the music as a hack job. (TV Tropes)