Yuri Karlovich Arnold, also Jury, Georgy, Yourij, and Arnol't, Arnol'd, was a Russian composer, musicologist, music critic, choral conductor, theorist and music educator. There is some speculation that he was employed by the tsarist police and that some of the writings attributed to him were actually written by Peshenin, who was paid to keep it a secret. Also that some of his theories on the history of Russian church music are now seen as false. Among his students were Allemanov and Yu Mel’gunov.