In 1889 Rimsky-Korsakov began a fourth opera, the history of which is connected with the co-operative tendency that distinguished the national school of musicians. The composition of collective works was, I believe, one of Balakirev's early ideals; the Paraphrases, a set of clever variations on a childish theme, dedicated to Liszt by Borodin, Cui, Liadov and Rimsky-Korsakov, and the Quartet in honour of Balaiev are examples of this spirit of combination. In 1872 Gedeonov, then Director of the Opera, proposed that Borodin, Moussorgsky, Cui and Rimsky-Korsakov should each undertake one act of a ballet-opera for a plot of his own providing, entitled _Mlada_. The music was written, but lack of funds prevented the enterprise from being carried out, and each composer utilised the material left on his hands in his own way. Rimsky-Korsakov incorporated his share with the fantastic scenes of _A Night in May_. In 1889, however, he took up the subject once more and _Mlada_ was completed by the autumn of the same year. Produced at the Maryinsky Theatre in October 1892, it failed to win the success it undoubtedly deserved. In the opera the part of Prince Mstivoy was taken by Stravinsky, and that of the Czech minstrel, Liumir, by Dolina. In the ballet, the Shade of Mlada was represented by the famous _ballerina_ Petipa, and the Shade of Cleopatra by Skorsiouka. The subject is taken from the history of the Baltic Slavs in the ninth century; but although in this work he returns to an historical episode, the composer does not go back to the declamatory style of _The Maid of Pskov_. Cheshikin considers that _Mlada_ is highly effective from the theatrical point of view. Moreover, the old Slavonic character of the music is cleverly maintained throughout, the ordinary minor scale being replaced by the "natural minor" (the Æolian Mode). The scenes representing the ancient Pagan customs of the Slavs are highly picturesque and, except on the grounds of its expensive setting, it is difficult to understand why this work should have passed out of the repertory of the Russian opera. The most distinctly humorous of all Rimsky-Korsakov's operas is the _Christmas Eve Revels_, a subject also treated by Tchaikovsky under the title of _Cherevichek_ and re-published as _Le Caprice d'Oxane_. The composer, as we have seen, rarely went outside his own land for literary material. But even within this circle of national subjects there exist many shades of thought and sentiment. Gogol's characters differ widely from those portrayed in such a legend as "Sadko." The Malo-Russian and Cossack population are more vivacious, and also more dreamy and sentimental, than the Great Russians. In fact the difference between the inhabitants of the Ukraine and those of the government of Novgorod is as great as that between a southern Irishman and a Yorkshireman, and lies much in the same directions.