Sadko, Op. 5, is a "musical tableau" by Nikolai Rimsky-Korsakov, written in 1867 and revised in 1869 and 1892. It is sometimes called the first symphonic poem written in Russia. It was first performed in 1867 at a concert of the Russian Musical Society (RMS), conducted by Mily Balakirev. Rimsky-Korsakov later wrote an opera of the same name which quotes freely from the earlier work. From the tone poem the composer quoted its most memorable passages in the opera, including the opening theme of the swelling sea, and other themes as leitmotives - he himself set out to "utilize for this opera the material of my symphonic poem, and, in any event, to make use of its motives as leading motives for the opera".