Of all the forms of Russian music it is perhaps in the Art-Song that we find the most comprehensive picture of this diverse and colourful people. The fact that Russia is not a country, but a continent, comprising many different races, tongues, customs and traditions accounts as much as any other single factor for the rich variety of their folklore. But in all this diversity there was one unifying factor: the vast illiterate masses were bound together by centuries of oppression; suffering and poverty were their common lot, their normal, accepted condition. Forced by the monotony of their miserable existence to find an outlet for their emotions, they found expression for their rich phantasy and alleviation of their frustration in Song and Dance. This produced a wealth of folklore, varied in rhythm and colour, which came to life a little more than a hundred years ago when Glinka discovered the treasures of this folklore and made use of them in his operas A Life for the Tsar and Russian and Ludmilla.